Dissertations / Theses: 'Transport energy efficiency'

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Stanovskyi, Yevhen. "Energy efficient transport and equipment." Thesis, Дніпропетровський національний університет залізничного транспорту ім. академіка В. Лазаряна, 2017. https://er.knutd.edu.ua/handle/123456789/9142.

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The purpose of the article is to emphasise the importance of energy efficient transport and equipment as the world practice demonstrates that increase in energy efficiency is the most effective direction of ensuring energy security of the country.
Автори статті приділяють увагу питанню важливості використання енергоощадного транспорту та обладнання, так як світовий досвід демонструє, що посилення заходів з енергозбереження є найбільш ефективним способом гарантування енергобезпеки країни.
Авторы статьи уделяют внимание важности проблеме использования энергосберегающего транспорта и оборудования, так как мировой опыт демонстрирует, что усиление мер по рациональному использованию энергии является наиболее эффективным способом обеспечения гарантии энергобезопасности страны.

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Akena, p'Ojok Robert. "Improving road transport energy efficiency through driver training." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5275/.

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Fuel consumption by road vehicles is the most significant component of total road transport energy use and is significantly affected by driving style. This research was aimed at improving the effectiveness and efficiency of driver training for fuel economy for drivers involved in the management and operations of a road network in England. A unique approach to driver training was designed and tested with 94 drivers of heavy, medium and light vehicles. The improvement in fuel economy (in terms of MPG) for the first month after the training was observed to improve by up to 7%. The improvements reduced at varying rates after the training suggesting the need for regular refresher training. The behaviours of the drivers were also observed to change as a result of the training, towards styles more suited to achieving a better fuel economy. The results suggest that both linear and logarithmic models could be suited to predicting the drivers' performances and could be integrated in models of the type of HDM-4 which currently lack such capability. The driver training methodology was found to be more cost effective than the Safe And Fuel Efficient Driving (SAFED) training method recommended by the Department for Transport (DfT).

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Kałuża, Andrzej. "Socioeconomic assessment and improvement of energy-efficiency in city rail transport /." Katowice : Komel, 2004. http://www.gbv.de/dms/bs/toc/493090088.pdf.

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Xylia, Maria. "Is energy efficiency the forgotten key to successful energy policy? : Investigating the Swedish case." Licentiate thesis, KTH, Energi och klimatstudier, ECS, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-192291.

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Sweden aims to become one of the first fossil-free welfare countries in the world. In 2009, specific energy and climate policy targets were announced for 2020, which exceed the ambition of respective EU targets in some areas. The overarching objective of the thesis is to understand the role of energy efficiency in Swedish energy and climate policy frameworks, and identify the gaps that need to be addressed. In this context, energy efficiency is recognized as a challenge to address. Yet, there are reasons to believe that it is not being pursued with the same dedication as other energy and climate-related targets. This hypothesis is tested using Mixed Methods research, with cases on different sectors of the Swedish economy, namely energy intensive industry and public bus transport, as well as comparisons with energy efficiency within the EU-28. With the help of abductive reasoning, the observations are inferred to an explanation, and common themes for Swedish energy efficiency policies emerge. The evidence indicates that energy efficiency has received lower priority than other energy and climate policies. This is demonstrated by the conflict between energy efficiency, emission reduction and renewable energy targets, for example in the case of public transport. There is generally a mismatch between targets and the instruments in place. Thus more attention should be given to energy efficiency and its potential benefits for the Swedish energy system. Opportunities for energy efficiency improvements are not being fully realized, but new policy initiatives could provide the necessary support to harness the potential. In-depth evaluation of new policy instruments should be integrated in the policy-making process, in order to provide a clear picture of costs versus benefits. An example is given with a Cost-Benefit Analysis for energy efficiency obligations targeting the Swedish energy intensive industry. Simplicity and transparency in the introduction and monitoring of new instruments need to be sought for. Energy efficiency should be given first priority in relation to other energy and climate targets. The basis for future policies should be grounded now in order for energy efficiency to become the key for successful Swedish energy policy.

QC 20160914

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Pickering, Jason C. Pickering. "Understanding Coulombic Efficiency Limitations in an Acid-Base Energy Storage System: Mass Transport Through Nafion." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1528397906336044.

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Peake, Stephen Robert. "Cross-sector policy research : insights from the UK energy and transport sectors." Thesis, University of Cambridge, 1993. https://www.repository.cam.ac.uk/handle/1810/244626.

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Following established traditions in anthropology and sociology, where cross-border research helps to identify important themes which benefit from comparative study, this dissertation introduces cross-sector policy research as a new methodology for generating useful insights about public policy. The cross-sector method is applied to the study of the UK energy and transport sectors. A range of generic policy developments in the energy sector are identified including: the development of efficiency indicators, scenario analysis, and the establishment of energy efficiency programmes. Such developments have not, as yet, occurred in the transport sector. A structural analogy between energy and transport is developed which is used to generate a range of innovations for transport policy including: gross mass movements and intensities as indicators of the efficiency with which the economy uses transport; the projection of a quantitative scenario of sustainable mobility; and the outline of a transport efficiency programme. The insights from the analogy are generalised to consider the benefits of a wider application of cross-sector policy research to other policy areas.

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Kamiya, Norikazu. "Classical Reduction of Quantum Master Equations as Similarity Transformation." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199085.

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Nordström, Erik. "Advanced Modelling and Energy Efficiency Prediction for Road Vehicles." Thesis, Umeå universitet, Institutionen för fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-175358.

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This thesis presents a first real world case-study of road transport operations that use the COVER format, in which the driver and the vehicle are regarded as separate entities. This format enables a complex representation of the transport operation that potentially better describe reality compared to the conventional representation used in today’s certification tools. The representation of operations treated in this thesis is called Operating Cycles and has been used to fully describe three representative transport missions from a case-study truck. Stochastically generated operating cycles have been used to create a large data set and thus prevent overfitting of specific cycles. The Operating Cycle-representation allowed for fair comparison between vehicle designs and ultimately manifested a vehicle composition that reduced the fuel consumption by nearly 10% for the same kind of transport operations.

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Wang, Huajun. "Interplay between capacity and energy consumption in C-RAN transport network design." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-204939.

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Current mobile network architecture is facing a big challenge as the traffic demands have been increasing dramatically these years. Explosive mobile data demands are driving a significant growth in energy consumption in mobile networks, as well as the cost and carbon footprints [1]. In 2010, China Mobile Research Institute proposed Cloud Radio Access Network (C-RAN) [2], which has been regarded as one of the most promising architecture to solve the challenge of operators. In C-RAN, the baseband units (BBU) are decoupled from the remote radio units (RRH) and centralized in one or more locations. The feasibility of combination of implementing the very tight radio coordination schemes and sharing baseband processing and cooling system resources proves to be the two main advantages of C-RAN compared to traditional RAN. More importantly, mobile operators can quickly deploy RRHs to expand and make upgrades to their networks. Therefore, the C-RAN has been advocated by both operators and equipment vendors as a means to achieve the significant performance gains required for 5G [3]. However, one of the biggest barriers has shown up in the deployment of C-RAN as the novel architecture imposes very high capacity requirement on the transport network between the RRHs and BBUs, which is been called fronthaul network. With the implementation of 5G wireless system using advanced multi-antenna transmission (MIMO), the capacity requirement would go further up, as well as the power consumption. One solution has been proposed to solve the problem is to have the baseband functions divided, partially staying with RRHs and other functions would be centralized in BBU pool. Different splitting solutions has been proposed in [4] [5] and [6]. In this thesis work, we choose four different splitting solutions to build four CRAN architecture models. Under one specific case scenario with the fixed number of LTE base stations, we calculate the transport capacity requirement for fronthaul and adopt three different fronthaul technology. The power consumption is calculated by adding up the power utilized by RRHs, fronthaul network and baseband processing. By comparing the numerical results, split 1 and 2 shows the best results while split 2 is more practical for dense cell area, since split 1 requires large fronthaul capacity. The fronthaul transport technology can be decided according to different density of base stations. TWDM-PON shows better energy performance as fronthaul network when the capacity requirement is high, compared to EPON. However, for larger number of BSs, mm-Wave fronthaul is a better solution in terms of energy efficiency, fiber saving and flexibility.

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Zhou, Jing. "Improving the energy efficiency of high speed rail and life cycle comparison with other modes of transport." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/25066.

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The world energy crisis and global warming call for a reduction of energy consumption. High speed rail, increasingly viewed as an effective solution to inter-city passenger transportation challenge of the 21st century, has the significant ability of increasing passenger capacity and reducing journey time. The advent of high speed rail provided many research opportunities. So far studies have been contributed from different perspectives: economical, environmental, and technical. The main research gaps are: addressing the problem of the effects of route geometry on train energy consumption and quantifying the contributing factors towards differences in energy consumption between different types of high speed trains. In addition, this energy assessment cannot be based solely on the energy consumption in the operation phase. In the life cycle assessment of the whole railway system, the vehicle evaluation is relatively straightforward, but the infrastructure raises many difficult issues. In this thesis, an existing approach for modelling the traction energy of electric trains is developed and extended to simulate the train operation under different driving strategies. Baseline simulation is carried out to estimate the journey time and energy consumption of a High Speed 2(HS2) reference train running on the London-Birmingham proposed high speed route. The influence of route geometry and train configuration on energy consumption is investigated, based on the metric of energy consumption per passenger kilometre. Simulations are also carried out of different types of high speed rolling stock running on the proposed HS2 route, to identify the key areas of vehicle design which help to minimise the energy consumption of high speed rail travel. The life cycle assessment of railway infrastructure is carried out in four stages of a whole life cycle: production, operation, maintenance and disposal, the influence of route parameters on life cycle cost is also investigated. Finally, high speed rail is compared with competing modes of transport, i.e. the aircraft, the automobile and the conventional train, in both operational energy efficiency and whole life cycle analysis. The high speed rail transportation has great advantage over the road and air transport, giving a reduction of carbon emission by roughly 95%, among which the operation stage contributes the largest reduction.

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Ajayi, Adeyemi Kazeem. "New Housing Developments: A Localisation Strategy considering Energy-Efficiency from an Urban Structure and Transport Perspective for the city of Falun." Thesis, Högskolan Dalarna, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:du-34469.

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There are several considerations when planning new housing developments, and resultant problems require critical analysis. This thesis has focused on studying some part of the potential issues in the case of a project in the city of Falun. The focus has been on energy and greenhouse gases (GHG)-efficient structures, through the analysis of the relationship between the transport system and residential development that can contribute to the reduction in emission’s harmful effect on human health and the environment. The overall aim has been on the sustainable location of housing with regards to transport energy, and it included the review of densification in the development of city planning as a measure. These courses of action, together with other considered measures been explored, are to provide solutions which can contribute to the livability, a greener environment and lower the levels of GHG, as well as the use of energy from transport. Densification is a significant concern when planning for future infrastructure and developments in a city. It is not just about housing; dense cities use less energy and the denser a city, the more sustainable they set to be. The significance of the transport system in an urban environment is enormous due to the level of its impact as a major user of energy, specifically petroleum product consumption. It is essential to note the importance of the effect that GHG and energy use from transport has on the health and wellbeing of city inhabitants, the society, as well as humans in general. Therefore, it is most important to strive to reduce the need for energy use from transport and to lower the levels of transport GHG. The city of Falun is planning for new housing development, with comprehensive plans for future urban development of areas within and around the city. There is a current proposal for the densification of central areas; however, they are also proposing new large areas on the periphery, which may be counter-productive from a transport point of view. This circumstance could lead to more car travel within and around the city, which leads to increases in carbon dioxide (CO2) emissions and fuel use, and in turn, increased in environmental pollution. Thus, the thesis purpose has been to investigate the energy use and carbon dioxide emissions in related scenarios. The aim is studying the proposed new housing development potentials to reduce car travel through an urban strategy measure such as smart growth; therefore, the selection of the following research questions below: • Will the proposal in the detailed, comprehensive plan lead to transportation that is more or less energy-efficient than today? And Is the proposed development in line with previous empirical findings in the research literature? • Can the amount of car travel be reduced by planning for a different location strategy for future residential development in Falun? • Can this analysis be made roughly using simple tools that are easy to use for urban planners or architects (not only for advanced GIS-engineers and researchers) iv A literature review facilitates reflection on these issues and studies measures for strategies which could be a better alternative when exploited in such or similar situation for preferable development. Thus, it’s exploitation in the thesis work. This research has been carried out by performing an investigation of the new housing development proposal, specifically through analyses of the assumed additional usage of passenger cars in the ongoing planned area. Possible alternatives are, therefore, examined, e.g. in the frame of options such as spreading the housing system into more centrally located and connecting areas, improving the relationship between the public transport system and new residential development so they could work in tandem. From the carried-out work, it has possible to be able to identify some disharmony in the ongoing development plans as part of the possible future problems, i.e. the case of possible unexploited solution for air pollution from transport energy, related issues, and so on. An in-depth interview with two of the Falun city office staffs and planners also opens-up on the problems of decision-makers and land use policy. Also, site visits provide the perspectives of present and potential owners who participated in an impromptu interview. Meanwhile, the presented results show that the overall total energy usage becomes higher per person with the Falun city´s ongoing-planning proposal, but lower with the designed alternative planning scenario. The results were derived through calculations, using the “Model for calculating energy use and carbon dioxide emissions in different scenarios’’ for generating scenarios that take modal split into account as seen in the data, calculation and result’s chapter, further in the thesis.
Det finns flera omständigheter när man planerar nya bostadsutvecklingar och de resulterande utmaningarna kräver kritisk analys. Detta examensarbete avhandling har genomförts genom att studera några av de potentiella problemen i fallet med ett projekt i Falun. Fokus ligger på energi- och växthusgaser effektiva strukturer genom att analysera förhållandet mellan transportsystemet och bostadsutveckling som kan bidra till att sänka utsläppars skadlig effekt och för att skapa en bättre livskvalitet och miljö. Huvudmålet ligger på hållbar lokalisering av bostäder och hur transportenergin från resande påverkas, det innefattar hur en kombinering med förtätning av utvecklingen i stadsplaneringen som en åtgärd. Detta, tillsammans med andra övervägda åtgärder för att tillhandahålla lösningar som kan bidra till livbarhet, en grönare miljö och sänka nivåerna av växthusgaser samt användning av energi från transporter. Förtätning är en stor angelägenhet när man planerar framtida infrastruktur och utveckling. Det handlar inte bara om bostäder; täta städer använder mindre energi och ju tätare stad desto mer hållbar kommer den att vara. Betydelsen av transportsystemet i en stadsmiljö är mycket stort på grund av nivån av dess inverkan som en stor energianvändare, specifikt petroleumsproduktförbrukningen. Det är väsentlig att notera vikten av effekten av utsläpp av växthusgaser och energianvändning från transporter på hälsan och välbefinnandet hos stadsinvånare och människorna i allmänhet. Därför är det viktig att sträva mot målet att minska behovet av energianvändning från transporter och sänka transportnivåernas utsläpp av växthusgaser. Falu stads planering är omfattande när det gäller stadsutveclklingen av områden inom och runtom staden. Det finns ett aktuellt förslag till förtätning av centrala områden. Dessutom förstår de också nya stora områden i förorterna vilket kanske var kontraproduktivt från transportsynpunkt. Detta kommer med sannolikhet att leda till fler bilresor, vilket leder till ökad koldioxidutsläpp och bränsleanvändning, vilket i sin tur ökar miljöföroreningarna. Således har syftet med avhandlingen ligger på att undersöka energianvändningen och koldioxidutsläppen i relaterade scenarier. Med syfte att studera de föreslagna av nya bostadsutvecklings potentialerna för att sänka biltrafiken genom en urban strategi åtgärd sasom smart tillväxt, därför är följande forskningsfrågor beaktade: • Förslaget i den detaljerade omfattande planen kommer att leda till transportation som är mer eller mindre energieffektiva än nu för tiden? och är den föreslagna utvecklingen i linje med tidigare empiriska fynd i forsknings litteraturen? • Kan mängden av bilresor sänkas genom att planera för en annan lokalisering strategi för framtida bostadsutveckling i Falun? • Kan den här analys göras grovt med enkla verktyg som är lätta att använda för stadsplanerare eller arkitekter (och inte bara för avancerade GIS-ingenjörer och forskare) En litteraturstudie underlättar reflektion över sådana frågor och ger åtgärder för en strategi som borde kunna lösa situationen för bättre utveckling. vi Denna forskning kommer att har genomförts genom en undersökning av det nya bostadsutvecklingsförslaget, specifkt genom analyser av den antagna transportfrågan inom det pågaende planarat området. Möjliga lösningar kommer bli presenterade, t.ex. för att skapa andra alternativ att sprida bostadssystemet till mer centralt beläget och anslutande områden, förbättra förhållandet mellan det offentliga transportsystemet och den nya bostadsutvecklingen så att de fungerar hand-i-hand. Från det arbete som har gjorts har jag kunnat identifiera disharmonin i de pågående utvecklingsplanerna som en del av eventuella framtida problem, dvs ärendet med en eventuell outnyttjad lösning för luftföroreningar från transportenergi, relaterade frågor och så vidare. En djupintervju med två av Falun stadskontors personal och planerare också öppnar upp vid beslutsfattarnas problem och markanvändningspolitik. Besök på plats ger perspektiv från nuvarande och potentiella ägare som deltog i en improviserad intervju. Emellertid, visade de presenterade resultaten att den helhets- totala energianvändningen blir högre per person från Falun stadens pågående planeringsförslag, men lägre med mitt eget utformade alternativa planeringsscenario. Resultats härleddes genom beräkningar, med hjälp av "Model för beräkning av energi användning och koldioxidutsläpp i olika scenarier'' för att generera scenarier som tar hänsyn till modal split som ses vidare i uppsatsens data, beräkning och resultat kapitel.

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Nassiep, Kadri Middlekoop. "An energy efficient mass transportation model for Gauteng / Kadri Middlekoop Nassiep." Thesis, North-West University, 2011. http://hdl.handle.net/10394/8076.

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The demand for forensic social work as a specialist field is increasing rapidly, due to the increasing moral decline of the community and consequent higher demands set to generic social workers. Amendments to existing acts as well as the development of new legislation, lead to more opportunity for the prosecution of the perpetrator, and therefore a higher utilization of the forensic social worker. A need was experienced to do research regarding the gaps experienced by social workers or any other workers who are currently executing forensic assessments with the sexually traumatised child. The aim of the investigation was to determine which gaps social workers experience in the field when assessing a child forensically. A recording procedure was used to obtain qualitative as well as quantitative data. A purposive sampling was used were interviews were held with five participants to obtain the data. A selfdeveloped questionnaire was used as measuring instrument. It is clear from the findings that there are definite gaps within the field of forensic social work and the need of further research within the field of forensic social work in South Africa is highlighted.
Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2012.

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Huang, Wei-Jie, and Wei-Jie Huang. "Towards Increased Photovoltaic Energy Generation Efficiency and Reliability: Quantum-Scale Spectral Sensitizers in Thin-Film Hybrid Devices and Microcracking in Monocrystalline Si." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/623175.

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The present work focuses on two strategies contributing to the development of high efficiency, cost-effective photovoltaic (PV) technology for renewable energy generation: the design of new materials offering enhanced opto-electronic performance and the investigation of material degradation processes and their role in predicting the long-term reliability of PV modules in the field. The first portion of the present work investigates the integration of a novel CdTe-ZnO nanocomposite material as a spectral sensitizer component within a thin-film, hybrid heterojunction (HJ) PV device structure. Quantum-scale semiconductors have the potential to improve PV device performance through enhanced spectral absorption and photocarrier transport. This is realized via appropriate design of the semiconductor nanophase (providing tunable spectral absorption) and its spatial distribution within an electrically active matrix (providing long-range charge transport). Here, CdTe nanocrystals, embedded in an electrically active ZnO matrix, form a nanocomposite (NC) offering control of both spectral absorption and photocarrier transport behavior through the manipulation of nanophase assembly (ensemble effects). A sequential radio- frequency (RF) magnetron sputter deposition technique affords the control of semiconductor nanophase spatial distribution relative to the HJ plane in a hybrid, ZnO-P3HT test structure. Energy conversion performance (current density-voltage (J-V) and external quantum efficiency (EQE) response) was examined as a function of the location of the CdTe nanophase absorber region using both one dimensional solar cell capacitance simulator (SCAPS) and the experimental examination of analogous P3HT-ZnO based hybrid thin films. Enhancement in simulated EQE over a spectral range consistent with the absorption region of the CdTe nanophase (i.e. 400–475 nm) is confirmed in the experimental studies. Moreover, a trend of decreasing quantum efficiency in this spectral range with increasing separation between the CdTe nanophase region and the heterojunction plane is observed. The results are interpreted in terms of carrier scattering/recombination length mitigating the successful transport of carriers across the junction. The second portion of the research addresses the need for robust PV performance in commercial module as a primary contributor to cost-effective operation in both distributed systems and utility scale generation systems. The understanding of physical and chemical mechanisms resulting in the degradation of materials of construction used in PV modules is needed to understand the contribution of these processes to module integrity and performance loss with time under varied application environments. In this context, the second part of present study addresses microcracking in Si–an established degradation process contributing to PV module power loss. The study isolates microcrack propagation in single-crystal Si, and investigates the effect of local environment (temperature, humidity) on microcrack elongation under applied strains. An investigation of microindenter-induced crack evolution with independent variation of both temperature and vapor density was pursued in PV-grade Si wafers. Under static tensile strain conditions, an increase in sub-critical crack elongation with increasing atmospheric water content was observed. To provide further insight into the potential physical and chemical conditions at the microcrack tip, micro-Raman measurements were performed. Preliminary results confirm a spatial variation in the frequency of the primary Si vibrational resonance within the crack-tip region, associated with local stress state, whose magnitude is influenced by environmental conditions during the period of applied static strain. The experimental effort was paired with molecular dynamics (MD) investigations of microcrack evolution in single-crystal Si to furnish additional insight into mechanical contributions to crack elongation. The MD results demonstrate that crack-tip energetics and associated cracking crystal planes and morphology are intimately related to the crack and applied strain orientations with respect to the principal crystallographic axes. The resulting fracture surface energy and the stress-strain response of the Si under these conditions form the basis for preliminary micro-scale peridynamics (PD) simulations of microcrack development under constant applied strain. These efforts were integrated with the experimental results to further inform the mechanisms contributing to this important degradation mode in Si-based photovoltaics.

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Sharif, Atif. "Reliable, congestion aware transport layer protocol for heterogeneous wireless sensor networks." Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/87.

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Energy is the biggest concern for any heterogeneous WSNs and achieving high energy efficiency is of paramount importance for the longevity of a heterogeneous WSNs. Communicating in- formation from the sensing region to the sink is a critical task in the entire operation of a heterogeneous WSNs. Such information needs to be reliably communicated, while avoiding any network congestion, from source to sink in order to ensure that application-specific Quality of Service objectives are met for any given scenario. This thesis developed several transport layer protocols to address the issues of congestion control, reliability assurance, simultaneously supporting heterogeneous traffic environment and energy efficiency for a heterogeneous WSNs.The first aim of the proposed research is to develop a congestion control scheme for a heterogeneous WSNs. The envisaged congestion control scheme has dual functionality. Firstly, it should be capable of handling the traffic heterogeneity and secondly, it intelligently assigns the source transmission rates and channel bandwidth for avoiding congested scenarios within the network, thereby avoiding any unnecessary packet retransmissions, due to packet drops caused by congestion. This produces high network good throughput, effective use of channel bandwidth, minimum E-2-E data packet latency etc. All the proposed transport layer protocol schemes e.g. End-to-End Reliable and Congestion Aware Transport Layer Protocol (ERCTP), Lightweight Congestion Aware Reliable Transport protocol (LCART) and Lightweight Congestion Aware Reliable Transport Protocol-implicit (LCARTi) are designed with this aim in mind.The second aim of the proposed research is to develop an intelligent reliability ensuring scheme capable of handling bidirectional reliability issues associated with data and control information flow within the heterogeneous WSNs. The design takes into account the variable nature of reliability assurance based on the nature of the traffic. For instance, multimedia flow is given a high reliability measure in comparison to scalar and non-event information flow, since the multimedia has a high retransmission cost. All the proposed transport layer protocol schemes such as ERCTP, LCART and LCARTi are designed in order to achieve this objective.The third aim of the proposed research is to develop a scheme that simultaneously handles the heterogeneous traffic flows within the same network. The proposed scheme has the intelligence to determine the nature of traffic and to allocate different bandwidth based on this nature in order to meet the stringent requirements as imposed by the application-specific QoS constraints like E-2-E data packet latency, high good throughput etc. All the proposed transport layer protocol schemes such as ERCTP, LCART and LCARTi are designed with this objective in mind.The fourth and final aim of the proposed research is to create a mechanism that merges the common functionalities of different layers of the WSNs communication stack in order to maximise energy efficiency. This involves finding the relationship between the transport and the lower MAC and wireless-physical layers of the WSNs communication stack. This merging will result in better utilization of network resources such as bandwidth, storage etc. and helps to achieve the objective of energy efficiency. Only the LCART and LCARTi designs achieve this proposed research aim.

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Fuentes, Pineda Rosinda. "Triphenylamine-based hole transport materials for perovskite solar cells." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31410.

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The rapid development in perovskite solar cells (PSC) has generated a tremendous interest in the photovoltaic community. The power conversion efficiency (PCE) of these devices has increased from 3.8% in 2009 to a recent certified efficiency of over 20% which is mainly the product of the remarkable properties of the perovskite absorber material. One of the most important advances occurred with the replacement of the liquid electrolyte with a solid state hole conductor which enhanced PCE values and improved the device stability. Spiro-OMeTAD (2,2',7,7'-tetrakis(N,N'-di-p-methoxyphenylamine)- 9,9'-spirobifluorene) is the most common hole transport material in perovskite solar cells. Nevertheless, the poor conductivity, low charge transport and expensive synthetic procedure and purification have limited its commercialisation. Triphenylamines (TPA) like Spiro-OMeTAD are commonly employed due to the easy oxidation of the nitrogen centre and good charge transport. Other triarylamines have similar properties to Spiro-OMeTAD but are easier to synthesise. The aim of this doctoral thesis is to investigate different types of hole transport materials in perovskite solar cells. Three different series of triphenylamine-based HTM were designed, synthesised, characterised and studied their function in perovskite solar cells. A series of five diacetylide-triphenylamine (DATPA) derivatives (Chapter 3) with different alkyl chain length in the para position was successfully synthesised through a five step synthesis procedure. A range of characterisation techniques was carried out on the molecules including; optical, electrochemical, thermal and computational methods. The results show that the new HTMs have desirable optical and electrochemical properties, with absorption in the UV, a reversible redox property and a suitable highest occupied molecular orbital (HOMO) energy level for hole transport. Perovskite solar cell device performances were studied and discussed in detail. This project studied the effect of varying the alkyl chain length on structurally similar triarylamine-based hole transport materials on their thermal, optical, electrochemical and charge transport properties as well as their molecular packing and solar cell parameters, thus providing insightful information on the design of hole transport materials in the future. The methoxy derivative showed the best semiconductive properties with the highest charge mobility, better interfacial charge transfer properties and highest PCE value (5.63%). The use of p-type semiconducting polymers are advantageous over small molecules because of their simple deposition, low cost and reproducibility. Styrenic triarylamines (Chapter 4) were prepared by the Hartwig-Buchwald coupling followed by their radical polymerization. All monomers and polymers were fully characterised through electrochemical, spectroscopic and computational techniques showing suitable HOMO energy levels and desirable optoelectrochemical properties. The properties and performance of these monomers and polymers as HTMs in perovskite solar cells were compared in terms of their structure. Despite the lower efficiencies, the polymers showed superior reproducibility on each of the device parameters in comparison with the monomers and spiro-OMeTAD. Finally, star-shaped structures combine the advantages of both small molecules, like well-defined structures and physical properties, and polymers such as good thermal stability. Two star-shaped triarylamine-based molecules (Chapter 5) were synthesised, fully characterised and their function as hole-transport materials in perovskite solar cells studied. These materials afford a PCE of 13.63% and high reproducibility and device stability. In total this work provided three series of triarylamine-based hole transport materials for perovskite solar cells application and enabled a comparison of the pros and cons of different design structures: small-molecule, polymeric and star-shaped.

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Wallace, Andrew. "Reducing carbon emissions by households : the effects of footprinting and personal allowances." Thesis, De Montfort University, 2009. http://hdl.handle.net/2086/2402.

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Nearly half of Britain’s carbon dioxide emissions result from the activity of households, both within the home and from personal transport. This research examines how the carbon dioxide emissions of households can be reduced, particularly through the calculation of carbon footprints and testing the public’s reaction to the concept of personal carbon allowances (PCAs). Two data collection stages were used - a postal survey providing quantitative data, followed by semi-structured interviews producing mainly qualitative data. The research was carried out in a largely rural district which is run by a council noted for its work on sustainable energy, Newark and Sherwood. The survey looked at PCAs as well as a variety of contemporary issues that might influence household footprints such as energy efficiency grants and information, as well as relationships with gas and electricity suppliers. Each interview involved the calculation of a household carbon footprint, the identification of measures to reduce it, and the gathering of attitudes about personal carbon allowances, in order to identify challenges and opportunities with respect to reducing household carbon emissions. Support for PCAs was higher than anticipated, and tended to be associated with those who were prepared to use public transport or cycle more, or were supportive of renewable energy in homes. Interviewees had much to say about individual carbon reducing measures. Opposition was associated with those who envisaged that they would be unlikely to sell carbon units. Regarding personal transport, long commutes were common, and the cost of public transport was of concern. Specific findings were made about domestic heating, insulation, lighting, refrigeration, water use, commuting, public transport, and rail as an alternative to short-haul flights. There was more interest in monetary savings than carbon savings. Recommendations about policy and regarding further research are made.

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Nygren, Johan. "On the impact of noise and energy demand from traffic : An assessment using microscopic modelling." Licentiate thesis, KTH, Marcus Wallenberg Laboratoriet MWL, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292360.

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Noise emissions from transportation remain one of the greatest environmental issues of modern day. Inhabitants in urban environments are especially exposed, with almost 80 million people in the European Union exposed to noise levels exceeding the recommended limits set by the World Health Organization (WHO). While the health-related effects from exposure of traffic noise are problematic and of utmost importance to reduce, availability to efficient transport is also an essential necessity. These conflicting requirements on transportation calls for a more holistic approach to traffic analysis, and to understand the relation between these effects from the traffic. This work investigates properties of traffic, such as the exposure of noise emissions, the vehicle-specific energy demand and duration, to analyse the sustainability of transport. The traffic simulation software SUMO is used to provide a discrete traffic model with individual vehicles, combined with the European vehicle noise source model IMAGINE used to model discrete sound sources that allow for directivity in the sound field and is speed- as well as acceleration-dependent. The resulting cost related to the exposure of noise is then evaluated at several measurement points in the network using a willingness-to-pay (WTP) model. This allows for an analysis of the relation between noise exposure cost and energy efficiency through the estimation of the vehicle-specific energy demand. A time-varying traffic demand is added to analyse the effects of a varying traffic density and congestion to the relation between the different properties. Additionally, the concept of allocating the noise exposure cost down to individual vehicles by means of contributed acoustic energy is expanded to take the main contributing vehicles and time-segments into consideration, and to allow for a non-linear weighting factor. These allocation strategies also allow for a bias to assign a higher cost to noisier vehicles, as vehicles that contribute more to the overall noise exposure than others may be more easily identified. Lastly, the relation between the traffic properties are analysed by means of correlation. Initial studies indicate that the correlation is dependent on the traffic density and the amount of vehicle interaction.
Trafikbuller är en av de största miljöproblemen idag. Invånare i stadsmiljöer är särskilt utsatta, där nära 80 miljoner personer i Europeiska Unionen är utsatta för bullernivåer som överskrider Världshälsoorganisationens (WHO) angivna gränsvärden. Medan de hälso-relaterade effekterna från exponering av buller är på en ohållbar nivå och bör reduceras, så är även tillgänglighet till effektiv transport en nödvändighet. Dessa motstridiga krav på transportnätverket kräver en mer holistisk syn på trafikanalys, för att förstå relationen mellan dessa effekter från trafiken. Detta arbete undersöker de effekter som uppstår från trafiken, såsom bullerexponering, det fordons-specifika energibehovet och tiden i trafiken, för att analysera hållbarhetsaspekter för transporter. I detta arbete används trafiksimuleringsprogrammet SUMO för att erhålla en diskret trafikmodell med individuella fordon, i kombination med den europeiska fordonsbullermodellen IMAGINE som används för att modellera diskreta bullerkällor som tar hänsyn till direktivitet i ljudfältet samt fart- och accelerationsberoende. Den resulterande kostnaden för bullerexponeringen beräknas därefter för ett stort antal mätpunkter i nätverket genom en modell för betalningsvilja (WTP). Detta tillåter en analys av förhållandet mellan kostnad från bullerexponering och energieffektivitet baserat på det fordonsspecifika energibehovet. Ett tidsvarierande trafikflöde läggs på för att analysera effekterna från en varierande trafiktäthet och trängsel på förhållandet mellan de olika egenskaperna. Dessutom expanderas konceptet att allokera den buller-relaterade kostnaden ner till enskilda fordon baserat på deras enskilda bullerbidrag. Detta för att potentiellt kunna allokera en större del av den totala kostnaden till fordon som bidrar särskilt mycket till den totala bullernivån eller till särskilda tidsegment med höga bullernivåer, samt att tillåta en ickelinjär viktfunktion. Dessa allokeringsstrategier ger också möjligheten att allokera en högre kostnad till bullriga fordon, då fordon som bidrar mer till den totala bullernivån kan lättare identifieras. Slutligen analyseras förhållandet mellan trafikegenskaperna utifrån korrelation. Inledande studier visar att korrelationen beror på trafiktätheten och mängden fordonsinteraktion i trafiken.

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Giacosa, Matteo. "Carbon dioxide abatement options for heavy-duty vehicles and future vehicle fleet scenarios for Finland, Sweden and Norway." Thesis, KTH, Energisystemanalys, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226144.

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Road transport is responsible for a significant share of the global GHG emissions. In order to address the increasing trend of road vehicle emissions, due to its heavy reliance on oil, Nordic countries have set ambitious goals and policies for the reduction of road transport GHG emissions. Despite the fact that the latest developments in the passenger car segment are leading towards the progressive electrification of the fleet, the decarbonization of heavy-duty vehicle segment presents significant challenges that are yet to be overcome. This study focuses, on the first part, on the regulatory framework of fuel economy standards of road vehicles, highlighting the absence of a European regulation on fuel efficiency for the heavy-duty sector. Energy efficiency technologies can be grouped mainly in vehicle technologies, driveline and powertrain technologies, and alternative fuels. The fuel efficiency of HDVs can be positively improved at different vehicle levels, but the technology benefit and its economic feasibility are heavily dependent on the vehicle type and the operational cycle considered. The electrification pathway has the potential of reducing the carbon emission to a great extent, but the current battery technologies have proven to be not cost efficient for the heavy vehicles, because of the high purchase price and the low range, related to the battery cost and inferior energy density compared to conventional liquid fuels. A scenario development model has been created in order to estimate and quantify the impact of future developments and emission reduction measures in Finland, Sweden and Norway for the timeframe 2016-2050, with a focus on 2030 results. Two scenarios concerning the powertrain developments of heavy-duty vehicles and buses have been created, a conservative scenario and electric scenario, as well as vehicle efficiency improvements and fuel consumption scenarios. Additional sets of parameters have been estimated as input for the model, such as national transport need and load assumptions. The results highlight the challenges of achieving the national GHG emission reduction targets with the current measures in all three countries. The slow fleet renewal rates and the high forecasted increase of transport need limit the benefits of alternative and more efficient powertrains introduced in the fleet by new vehicles. The heavy-duty transport is expected to maintain its heavy reliance on diesel fuel and hinder the improvements of the light-duty segments. A holistic approach is needed to reduce the GHG emissions from road transport, including more efficient powertrains, higher biofuel shares and progressive electrification.

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Olander, Petra. "Tribology for Greener Combustion Engines : Scuffing in Marine Engines and a Lubricating Boric Acid Fuel Additive." Doctoral thesis, Uppsala universitet, Tillämpad materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-333430.

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This thesis aims at increased knowledge in two fields of tribological research; both related to making currently used combustion engines greener. The first field regards the possibilities of using a boric acid fuel additive to increase fuel efficiency. The second field is about the severe wear phenomenon scuffing, which can become problematic when cargo ships are operated on low-sulphur fuel to reduce sulphuric emissions. Tribological tests were developed and performed to simulate the applications. Advanced surface analysis was performed to understand changes occurring on the outermost surface of sliding components, which affect friction and wear. Samples from engines were studied to verify the relation between the lab tests and the applications. In the case of boric acid, the coefficient of friction was below 0.02 for large parts of the tests, but varied with test parameters. The corresponding reduction in friction was up to 78% compared with tests without the additive. As an attempt to assess if the substantial fuel savings found in field tests with passenger cars (6%) can be explained by friction reduction in boundary and mixed lubricated parts of the piston assembly, assumptions were presented that would lead to fuel savings close to these 6%. Boric acid was detected on surfaces after the tests, and the tribofilm appearance depended on test parameters. The tribofilms were shown to be affected by storage time and test temperature; a finding that is vital for future studies. In the case of scuffing, mechanisms were studied and accumulation of wear debris had a significant role on scuffing initiation in the lab scale scuffing tests. Regarding the possibility to test materials scuffing resistance, there was a large scatter in the results, and thereby difficult to draw conclusions. Two new piston ring materials were identified to perform somewhat better than the currently used. In conclusion, findings that could facilitate immediate improvement of fuel efficiency of today’s combustion engine vehicles as well as findings that strengthen available hypotheses on scuffing mechanisms are presented. The latter offers improved understanding of scuffing and thereby give possibilities to counteract the higher risk associated with operation on cleaner fuel.

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Marins, Karin Regina de Casas Castro. "Proposta metodológica para planejamento energético no desenvolvimento de áreas urbanas. O potencial da integração de estratégias e soluções em morfologia e mobilidade urbanas, edifícios, energia e meio ambiente: o caso da operação urbana Água Branca no município de São Paulo." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/16/16132/tde-09062010-155906/.

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O objeto da presente tese é o desenvolvimento de uma proposta metodológica para planejamento energético no desenvolvimento de áreas urbanas, na escala de distritos, bairros e unidades de vizinhança. A metodologia proposta é aplicável a estudos de desenvolvimento de novas áreas urbanas, distritos ou bairros e estudos para requalificação de áreas urbanas já ocupadas, como ferramenta de suporte ao planejamento e ao processo decisório. Inicialmente, foi produzida uma base referencial dos principais condicionantes para o planejamento energético urbano, segundo o escopo considerado nesse trabalho de pesquisa. Nessa etapa foram identificadas e analisadas as interdependências entre esses fatores e sua participação no consumo energético e nas emissões de poluentes. A proposta metodológica está estruturada em dois módulos principais: Módulo 1 - Gerenciamento da Demanda de Energia, envolvendo aspectos relacionados à Morfologia Urbana, Mobilidade Urbana e Edificações, tais como densidade populacional e construída, uso e ocupação do solo, geometria de quadras e cânion urbano, sistema de transporte urbano de passageiros, sistema viário, tecnologias veiculares e combustíveis, soluções passivas em conforto ambiental e substituição tecnológica de equipamentos em edificações; e Módulo 2 - Gerenciamento da Oferta de Energia, incluindo sistemas de geração e distribuição de energia elétrica e térmica para aquecimento e resfriamento em escala urbana, inclusive com aproveitamento de recursos energéticos residuais e renováveis. Dos Módulos 1 e 2 resultam os níveis de consumo de energia e as emissões totais de poluentes, incluindo Gases de Efeito Estufa e poluentes locais. Na composição da proposta metodológica participam variáveis e parâmetros relacionados aos condicionantes de planejamento energético urbano, bem como procedimentos de cálculo que integram e compatibilizam as configurações urbanas quanto à morfologia, mobilidade, edificações, e geração de energia. Os procedimentos foram sistematizados em um conjunto de planilhas eletrônicas e gráficos comparativos, desenvolvidos para aferição da proposta metodológica, suporte na visualização de resultados e indicadores e posterior aplicação como ferramenta no planejamento de áreas urbanas. A proposta metodológica foi aplicada no caso da Operação Urbana Água Branca, no Município de São Paulo, ficando demonstrado o potencial de integração de estratégias e comprovando a tese em questão. Nas duzentas e dezessete diferentes situações configuradas por meio da metodologia proposta, foi possível identificar não apenas importantes potenciais quantitativos, mas também a contribuição relativa dos diversos condicionantes para o resultado global, em termos energéticos, urbanísticos e ambientais. Além dos cenários apresentados, a proposta metodológica permite que diversos outros possam ser configurados para outras áreas urbanas a serem desenvolvidas ou requalificadas, desde que as variáveis e os parâmetros sejam adequadamente adaptados a cada realidade.
The subject of this thesis is the development of a methodology for energy planning in the development of urban areas, in the scale of districts and neighborhoods. The proposed methodology has two main applications as a tool to support strategic planning and decision-making process: studies for the development of new urban areas, districts or neighborhoods, and studies for rehabilitation of urban areas already used. Initially, a conceptual and technical approach was done about the main constraints for urban energy planning, according to the scope considered in this research. In this stage, the interrelationships among these factors and their impact in terms of energy consumption and pollutant emissions were identified and analyzed. The proposed methodology is organized into two main modules: Module 1 - Energy Demand Management, involving aspects of urban morphology, urban mobility and buildings, such as population density and built area, land use, urban blocks and urban canyon geometry, urban transport, road system, vehicle and fuel technologies, passive solutions to environmental comfort and technological replacement of equipment in buildings; and Module 2 - Energy Supply Management, including district and local systems for generating and distributing electricity and steam for heating and cooling purpose, including the use of renewable and waste energy resources. Levels of energy consumption and the total emission of pollutants, including greenhouse gases and local pollutants, result from the Modules 1 and 2. The proposed methodology involves variables and parameters related to the constraints of urban energy planning as well as calculation procedures that integrate and match the urban settings under consideration, as urban morphology, mobility, buildings, power generation and district systems. The procedures were systematized into a set of spreadsheets and charts developed to verify the proposed methodology, visualization support of results and indicators, and later application as a tool for planning of urban areas. The proposed methodology was applied to the Agua Branca Urban Operation study-case, in the city of Sao Paulo, in which the potential of integrating strategies was demonstrated. In thirty-six different situations defined by using the proposed methodology, it was possible to identify not only important quantitative potentials but also the relative contribution of various constraints to the overall result in terms of energy, urban and environmental issues. In addition to the scenarios presented, the proposed methodology allows the configuration of several other options to different urban areas to be developed or rehabilitated, but variables and parameters need to be properly adapted to each situation.

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Arruda, Tiago José. "Espalhamento de ondas eletromagnéticas por esferas e cilindros magnéticos: confinamento e transporte de ondas no limite de pequenas partículas e independência da energia armazenada com relação à forma do centro espalhador." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22122010-103549/.

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O espalhamento eletromagnético por uma esfera com propriedades ópticas e raio arbitrários, conhecido como espalhamento de Lorenz-Mie, ou por um cilindro circular infinito, pode ser resolvido analiticamente e é comumente tratado dentro da abordagem de espalhadores dielétricos. Na região óptica, tanto meio circundante quanto partícula espalhadora possuem o mesmo valor de permeabilidade magnética. A ausência do magnetismo nessa região do espectro torna o índice de refração relativo entre os meios interno e externo ao espalhador homogêneo equivalente ao respectivo índice de impedância óptica. Em regiões espectrais de micro-ondas ou radiofrequências, entretanto, materiais ferro- e ferrimagnéticos podem exibir valores absolutos de permeabilidade magnética extremamente elevados, reduzindo então a impedância óptica em comparação ao valor correspondente de índice de refração relativo. Uma característica marcante vinculada ao magnetismo no centro espalhador é que pequenas partículas comparadas com o comprimento de onda (parâmetros de tamanho na região de Rayleigh) podem apresentar grandes seções de choque de extinção a despeito de suas pequenas seções de choque geométricas. Isso torna possível, fisicamente, a presença de picos de ressonância morfológica na energia eletromagnética interna ao centro espalhador mesmo na região de parâmetros de tamanho inferiores à unidade. Em especial, mostramos que essa energia eletromagnética possui, no regime de fraca absorção, uma relação funcional simples com o comprimento de onda incidente e a seção de choque de absorção da partícula espalhadora, independentemente do formato geométrico da mesma. No espalhamento por uma coleção de partículas magnéticas, a velocidade de transporte de energia pode ser estimada a partir da energia eletromagnética média que é armazenada no interior de um centro espalhador isolado. Dessa maneira, a validade da relação universal que encontramos entre o fator de aumento da energia eletromagnética interna ao centro espalhador e sua correspondente seção de choque de absorção (no regime de baixa absorção óptica) implica na possibilidade de estimarmos de maneira simples a velocidade de transporte de energia em um meio desordenado. Um resultado decorrente dessa aproximação é que mesmo na região de Rayleigh a velocidade de transporte de energia em um meio magnético desordenado é drasticamente reduzida, levando, por conseguinte, à redução do coeficiente de difusividade dos fótons no meio. O estudo analítico e numérico da energia eletromagnética armazenada por uma esfera e por um cilindro magnéticos irradiados por ondas planas homogêneas são os temas em foco nesta dissertação de Mestrado.
Electromagnetic scattering by a sphere with arbitrary optical properties and radius, known as the Lorenz-Mie scattering, or by an infinite right circular cylinder can be solved analytically and is widely treated in the approach of dielectric scatterers. In the optical range, both embedding medium and scattering particle have the same magnetic permeability. The absence of magnetism in this spectral range leads to the equivalence between the relative refraction and impedance indices associated with the scatterers. However, in microwave or radio-frequency ranges, ferro- and ferrimagnetic materials can exhibit extremely huge values of magnetic permeability, which reduce the optical impedance in comparison to the corresponding value of relative refraction index. One striking feature associated with the magnetism in the scatterer is that particles smaller than the wavelength (Rayleigh size region) can present large extinction cross sections in despite of their small geometric cross sections. This becomes physically possible the presence of morphology-dependent resonances in the electromagnetic energy within the scatterer even in size parameters region smaller than unity. In particular, we show that this time-averaged electromagnetic energy has, in the weak absorption regime, a simple functional relation with the incident wavelength and the scatterer absorption cross section which does not depend on the shape of the scatterer. In the multiple scattering regime, the energy-transport velocity can be estimated from the time-averaged electromagnetic energy stored in a single scatterer. Thereby, the validity of the universal relation between the internal energy-enhancement factor and the absorption cross section respective to an arbitrary scattering center (in the weak absorption regime) implies that the energy-transport velocity in disordered media can be evaluated in a simple way. From this approximation, we obtain that even in the Rayleigh size region the energy-transport velocity in disordered magnetic media is dramatically reduced, which consequently leads to a reduction of the diffusion coefficient of the photons. The analytical and numerical studies of the time-averaged electromagnetic energy within magnetic isotropic spheres and cylinders irradiated by plane waves are our aim in this Master\'s degree dissertation.

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Abboubi, Adil El. "Étude et évaluation de la consommation énergétique d'une balise ferroviaire fondée sur l'ULB et le retournement temporel." Thesis, Valenciennes, 2016. http://www.theses.fr/2016VALE0009/document.

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Dans un contexte où les ressources énergétiques sont moindres et la demande en termes de débit de communication est forte, il est intéressant de proposer des solutions techniques au niveau de la couche physique permettant d’optimiser la consommation énergétique de systèmes. Actuellement, pour une localisation précise et un transfert de données entre voie et trains efficace, la signalisation ferroviaire exploite des balises disposées entre les rails. La durée possible de la communication entre trains et balises s’avère très brève et n’est effective que lorsque le train passe juste au-dessus de la balise. Celle-ci reste en état de veille jusqu’à ce que le train la télé alimente lors de son passage. Le temps de communication utile entre le train et la balise s’établit à 3-4 ms pour un train roulant à 300 km/h. Par conséquent, plusieurs équipements consécutifs doivent être installés si l’on veut accroître la durée d’échange ou encore la quantité de données échangées. En outre, le fait d’émettre continument un puissant signal de télé alimentation radiofréquence non exploité depuis tous les trains en circulation, la difficulté de maintenance liée à la présence de cet équipement entre les rails, ainsi que la portée et donc la capacité de communication réduites des balises actuelles constituent autant de limitations que nous tentons de pallier avec ce nouvel équipement. Dès lors, nous développons une nouvelle génération de balise ferroviaire fondée sur un lien radiofréquence qui possède une portée atteignant quelques mètres, nettement plus importante que celle exploitable actuellement. Cette balise est également située en bord de voie et non entre les rails pour des questions de facilité de maintenance. Nous utilisons une technique de focalisation du signal émis depuis la balise vers l’antenne embarquée sur le train. Puisque la distance de communication balise au sol - interrogateur est portée à quelques mètres, la télé alimentation par couplage inductif actuelle n’est plus possible. Disposer d’une infrastructure centrale pour alimenter toutes les balises présentes sur le réseau n’est pas réaliste non plus. Une solution raisonnable et économe consiste à générer de l’énergie électrique basse tension localement en utilisant des énergies renouvelables (solaire, éolienne…), et en limitant le plus possible la consommation d’énergie de l’électronique de la balise. Dans cette optique, la contribution scientifique présentée consiste à développer et à optimiser, en termes d’énergie consommée, la couche physique de communication de cet équipement
In railway signaling, accurate and safe localization of trains is of paramount importance for the safe exploitation of railway networks. Therefore, train odometry has received considerable interest. Usually, train odometers manage different embarked sensors including wheel counters and Doppler radars that compute the position and the speed of the trains. However, as trains move, these proprioceptive sensors accumulate drifts and, as a consequence, train localization accuracy is compromised after several kilometers. In order to fix this drift problem, railway signaling uses beacons installed at ground, on the track, between the rails. Installed every several kilometers, they transmit absolute localization information to trains passing over them thus, bringing back locally the drifts to zero. These beacons constitute major components of railway signaling and also one of the very last equipment installed between the rails. Existing railway beacons are placed on the rails for two main reasons. First of all, since in these conditions the radio link between the train and the beacons remains very short, in the order of a few tens of centimeters, placing the beacons on the rails is very helpful to deliver an accurate local absolute localization to the train. Moreover using this very short radio communication range, while passing over them, trains can supply electrical energy to the beacons by magnetically coupling radiofrequency energy from the train to the beacon. This radiofrequency energy is detected and converted in DC power supply to feed the beacon electronics. This very short range leads to a satisfactory transfer of energy between train and beacon. As indicated previously, beacons can just be position indicators; however, they can also handle communication between grounds and trains using a peer to peer radio link. In this case, communication is only active when the train passes over the beacons, thus, the effective communication time is very short. As another major drawback of this particular implementation between the rails, track maintenance requires disassembling the beacons and then repositioning them safely and accurately

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Bibri, Mohamed. "Sustaining ICT for Sustainability : Towards Mainstreaming De–carbonization–oriented Design & Enabling the Energy–Efficient, Low Carbon Economy." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-5936.

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The study set out to understand and demonstrate the role the ICT sector could play as a critical enabler in the transition and progress towards an energy– efficient, low carbon economy. More specifically, the study of sustaining ICT for sustainability has twofold intent: (2) to investigate the direct footprint of ICT sector and explore how it can be tackled through adopting sustainable design–based solutions; and (2) to highlight the enabling potential of ICT sector to mitigate climate change and massively improve energy efficiency across the economy, identifying and quantifying the global ICT impacts and opportunities in the context of energy and carbon emissions savings. To achieve the aim of this study, a pertinent and extensive literature review covering theoretical, empirical, and critical scholarship was performed to investigate the phenomenon. The study draws on a variety of sources to survey the unsustainability of ICT sector pertaining to energy–intensive consumption and explore potential solutions through espousing environmental design practice, and also to examine the role of ICT in delivering energy–efficient solutions through its products and services. Validity was ensured through using quality academic and industry literature as well as relevant studies carried out by a range of eminent researchers, experts, and stakeholders (i.e. NGOs, research centers). Findings highlight the unsustainability of ICT sector regarding energy– intensive consumption and concomitant GHG emissions associated with its products and services. Of the whole lifecycle, the use phase of ICT is the most critical. Data centers and telecom networks devour energy. Planned obsolescence entrenched in software design shorten upgrade cycle, which makes software utilities a planet killer as to energy consumption. Alternative sustainable design–based solutions entail using renewable energy and most efficient energy required over ICT’s life cycle – de–carbonization strategy. Also, digitization is an effective strategy for ICT sector to slash energy use per unit. To reduce the footprint of data centers and telecom networks, design solutions vary from hardware and software to technological improvements. Designing out built–in obsolescence in software technology is a key factor in the energy equation. As for the enabling role of ICT, the findings are highly illuminating. The ICT sector must step up its efforts in reducing its direct footprint in order to claim a leadership role in an energy–efficient, low carbon economy. Although the ICT sector’s own emissions will increase because of global growing demand for its products and services, the real gains will come from its enabling potential to yield substantial energy efficiency improvements and emissions reductions across the economy. The sheer scale of the climate change challenge presents smart development mitigation opportunities for ICT sector to deliver environmentally sustainable solutions. The largest identified opportunities are: dematerialization; intelligent transport and logistics; intelligent buildings; smart power supply; and efficient industrial processes and systems. This study provides a novel approach into sustainable design in ICT, underlining unsustainable design practices in ICT sector. Review of the literature makes an advance on extant reviews by highlighting the synergic relationship between ICT design, sustainability, and the economy.
+46 704 35 21 35

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Dahlqvist, Johan. "Cavity Purge Flows in High Pressure Turbines." Doctoral thesis, KTH, Kraft- och värmeteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-218468.

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Turbomachinery forms the principal prime mover in the energy and aviation industries. Due to its size, improvements to this fleet of machines have the potential of significant impact on global emissions. Due to high gas temperatures in stationary gas turbines and jet engines, areas of flow mixing and cooling are identified to benefit from continued research. Here, sensitive areas are cooled through cold air injection, but with the cost of power to compress the coolant to appropriate pressure. Further, the injection itself reduces output due to mixing losses.A turbine testing facility is center to the study, allowing measurement of cooling impact on a rotating low degree of reaction high pressure axial turbine. General performance, flow details, and cooling performance is quantified by output torque, pneumatic probes, and gas concentration measurement respectively. The methodology of simultaneously investigating the beneficial cooling and the detrimental mixing is aimed at the cavity purge flow, used to purge the wheelspace upstream of the rotor from hot main flow gas.Results show the tradeoff between turbine efficiency and cooling performance, with an efficiency penalty of 1.2 %-points for each percentage point of massflow ratio of purge. The simultaneous cooling effectiveness increase is about 40 %-points, and local impact on flow parameters downstream of the rotor is of the order of 2° altered turning and a Mach number delta of 0.01. It has also been showed that flow bypassing the rotor blading may be beneficial for cooling downstream.The results may be used to design turbines with less cooling. Detrimental effects of the remaining cooling may be minimized with the flow field knowledge. Stage performance is then optimized aerodynamically, mixing losses are reduced, and the cycle output is maximized due to the reduced compression work. The combination may be used to provide a significant benefit to the turbomachinery industry and reduced associated emissions.
Strömningsmaskinen i dess olika variationer bildar den främsta drivmotorn inom kraftproduktion och flygindustrin. En förbättring av denna väldiga maskinpark har potentialen till betydande inverkan på globala utsläpp. Områden som identifierats kunna dra nytta av vidare forskning är ombandningsprocesser och kylning. Dessa områden är inneboende i stationära gasturbiner och jetmotorer på grund av de heta gaser som används. Kylning uppnås genom injektion av kall luft i kritiska områden och försäkrar därmed säker drift. Kylningen kommer dock till en kostnad. På cykelnivå krävs arbete för att komprimera flödet till korrekt tryck. Dessutom medför injektionen i sig förluster som kan härledas till omblandningsprocessen. Syftet med detta arbete är att samtidigt undersöka de fördelaktiga kylegenskaperna som nackdelarna med inblandning för att på så sätt bestämma den uppoffring som måste göras för en viss kylning. Alla förbättringar tros dock inte behöva föregås av en uppoffring. Om påverkan av kylningen på huvudflödet är välförstådd kan designen justeras för att ta hänsyn till denna förändring och minimera inverkan. Denna metodologi riktar sig mot ett särskilt kylflöde, kavitetsrensningsflödet, som har till uppgift att avlägsna het luft från den kavitet som uppkommer uppströms rotorskivan i ett högtrycksturbinsteg. Studien kretsar kring en turbinprovanläggning som möjliggör detaljerade strömningsmätningar i ett roterande turbinsteg under inverkan av kavitetsrensningsflödet. Högtrycksturbinsteget som används för undersökningen är av låg reaktionsgrad. Här kvantifieras generell prestanda genom mätning av vridmomentet på utgående axel. Flödesfältet kvantifieras med pneumatiska sonder, och kylningsprestandan predikteras genom gaskoncentrationsmätningar. Resultaten visar avvägningen och sambandet mellan turbinverkningsgrad och kylning i kavitet samt huvudkanal. Flödet mäts i detalj, och de effekter som kan förväntas uppkomma då ett turbinsteg utsätts för en viss mängd av kylflödet kvantifieras. De kvantitativa resultaten för det undersökta steget visar på en förlust i verkningsgrad på 1.2 procentenheter för varje procentenhet av kavitetsrensningsflödet i termer om massflödesförhållande. Samtidigt ses kyleffektiviteten öka med 40 procentenheter. Den lokala inverkan på flödesfältet nedströms rotorn för det undersökta steget är 2° i flödesvinken och en ändring på 0.01 i Machnummer för varje procentenhet av kylflödet. Dessa ändringar ses i form av ökad omlänkning och reducerad hastighet nära hubben, och vice versa omkring halva spännvidden. Inverkan av aktuell driftpunkt understryks genom arbetet. Det har också visats att ett läckage som kringgår rotorbladen i vissa kan fall ge fördelaktig kylning i områden nedströms. Denna kombinerade kunskap kan användas för design av turbiner med så låg mängd kylning som möjligt samtidigt som säker drift bibehålls. Den negativa inverkan av den återstående kylningen kan minimeras genom kunskapen om hur flödesfältet påverkas. Genom detta optimeras stegverkningsgraden aerodynamiskt, omblandningsförluster minimeras, och cykeleffekten maximeras genom det minskade kompressionsarbetet till följd av de reducerade kylmängderna. Kombinationen kan ge en betydande förbättring för turbinindustrin och minskade utsläpp.

QC 20171129

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Cecone, Eduardo Christiano. "Modelagem energética de sistema de transporte pneumático utilizando planejamento fatorial." reponame:Repositório Institucional da UFABC, 2017.

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Orientador: Prof. Dr. Douglas Alves Cassiano
Em meados da década de 1920 tornou-se comum o emprego de sistemas pneumáticos destinados à movimentação de materiais particulados sólidos. As principais limitações para estas aplicações estão relacionadas a aspectos financeiros, em especial ao elevado consumo energético destes sistemas em comparação a outras tecnologias existentes, porém, a partir dos ganhos relacionados à eficiência energética, é fortemente recomendável considerar o seu emprego como primeira opção, mesmo em aplicações tradicionalmente mecânicas. Levantamento realizado junto à base de dados Elsevier-Scopus em 2017 aplicando-se os termos Pneumatic Conveying + Design of Experiments + Energy Efficiency, objetos deste trabalho, revelou a existência de apenas dois trabalhos publicados no ano de 2012. Assim o trabalho ora apresentado foi motivado pela necessidade de otimização da eficiência energética nestes sistemas e pela oportunidade de avanço da fronteira do conhecimento acerca do assunto evidenciadas pela pesquisa bibliográfica realizada. Fundamentado em técnicas estatísticas de planejamento fatorial e metodologia de superfície de resposta, o trabalho ora apresentado objetivou o estudo da eficiência energética de um sistema alternativo de transporte pneumático, que envolve os conceitos do transporte pneumático em fase densa e em fase diluída. Definido o material empregado no estudo (Alumina), realizaram-se ensaios de caracterização para investigação do seu potencial de fluidização, construiu-se um protótipo do ejetor pressurizado, definiram-se os planejamentos experimentais de dois níveis e composto central, realizaram-se 71 testes para obtenção de dados experimentais e obtiveram-se os modelos matemáticos linear e não linear que aplicados e interpretados, resultaram na superfície de resposta. Concluiu-se que o sistema proposto é capaz de realizar transporte pneumático nas condições do estudo. Observou-se que a eficiência energética do sistema pode ser adequadamente investigada e estudada a partir da metodologia adotada. Obtiveram-se o modelo matemático e a superfície de resposta que, validados, possibilitaram a inferência da eficiência energética do sistema em função da pressão de transporte e do tempo de dosagem de material, bem como a identificação do ponto ótimo de operação respeitadas as condições de contorno do estudo.
Tese ( doutorado)- Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2017.
In the mid-1920s it became common to use pneumatic systems for the movement of solid particulates. The main limitations for these applications are related to financial aspects, in particular the high energy consumption of these systems compared to other existing technologies, but, from the gains related to energy efficiency, it is strongly recommended to consider their use as the first option, even in traditionally mechanical applications. A survey carried out with the Elsevier-Scopus database in 2017 applying the terms Pneumatic Conveying + Design of Experiments + Energy Efficiency, objects of this work, revealed the existence of only two works published in the year 2012. Thus, the work presented here was motivated by the need to optimize energy efficiency in these systems and the opportunity to advance the frontier of knowledge about the subject evidenced by the bibliographical research. Based on statistical techniques of factorial planning and response surface methodology, the present study aimed to study the energy efficiency of an alternative pneumatic transport system, which involves the concepts of pneumatic transport in dense phase and in diluted phase. After the determination of the material used in the study (Alumina), characterization tests were carried out to investigate its fluidization potential, a prototype of the pressurized ejector was built, the experimental design of two levels and the central compound were defined, 71 tests to obtain experimental data and obtained the linear and non-linear mathematical models that applied and interpreted, resulted in the response surface. It was concluded that the proposed system is capable of performing pneumatic transport under the conditions of the study. It was observed that the energy efficiency of the system can be adequately investigated and studied from the methodology adopted. The mathematical model and the response surface were obtained, which validated the inference of the energy efficiency of the system as a function of the transport pressure and the material dosing time, as well as the identification of the optimum operating point, respecting the operating conditions.

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León, Montiel Roberto de Jesús. "Quantum-based spectroscopy and efficient energy transport with biomolecules." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/283108.

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For many years, the fields of quantum optics and biology have rarely shared a common path. In quantum optics, most of the concepts and techniques developed over the years stand for systems where only a few degrees of freedom are considered and, more importantly, where the systems under study are assumed to be completely isolated from their surrounding environment. This situation is far from what we can find in nature. Biological complexes are, by definition, warm, wet and noisy systems subjected to environmental fluctuations, where quantum phenomena are unlikely to be observed. Notwithstanding, in recent years, this paradigm has begun to be questioned by several works where quantum-mechanical concepts have been introduced in order to describe the dynamics of important biological processes, such as energy transport in photosynthetic light-harvesting complexes. The goal of this thesis is twofold. Firstly, we will investigate how ideas and techniques routinely used in quantum optics can be exploited in order to develop new quantum-based spectroscopy techniques and, secondly, we will examine to what extent microscopic quantum phenomena could impact on the efficient transport behavior of photosynthetic light-havesting complexes. This problem is particularly relevant, because the understanding of the fundamental mechanisms that enable the highly efficient transport of energy in photosynthetic systems could lead us to the design of future quantum-inspired light-harvesting technologies, such as high-efficiency organic solar cells.
Por muchos años, los campos de la óptica cuántica y la biología raramente han compartido un mismo camino. En la óptica cuántica, la mayoría de los conceptos y técnicas desarrolladas a lo largo de los años son válidas sólo en sistemas donde un número pequeño de grados de libertad es considerado y, más importante aún, donde se asume que los sistemas bajo estudio están completamente aislados del medio ambiente que los rodea. Esta situación está muy lejos de lo que podemos encontrar en la naturaleza. Los complejos biológicos son, por definición, sistemas a altas temperaturas, sujetos a fluctuaciones, en los cuales se cree que los fenómenos cuánticos son imposibles de observar. Sin embargo, en años recientes, esta creencia ha sido cuestionada por diferentes trabajos en los que conceptos de mecánica cuántica han sido usados con el objetivo de describir la dinámica de procesos biológicos de gran importancia como, por ejemplo, el transporte de energía en los complejos de captación de luz en sistemas fotosintéticos. El objetivo de esta tesis se divide en dos. Primeramente, investigaremos cómo las ideas y técnicas usadas comunmente en óptica cuántica pueden ser explotadas con el objetivo de desarrollar nuevas técnicas de espectroscopía y, segundo, estudiaremos hasta que punto los fenómenos cuánticos microscópicos pueden influir en el comportamiento del transporte eficiente de energía en sistemas fotosintéticos de captación de luz. Este problema es particularmente relevante, pues el entender los mecanismos fundamentales que permiten un eficiente transporte de energía en sistemas fotosintéticos nos podría conducir al diseño de nuevas tecnologías de captación y recolección de energía como, por ejemplo, celdas solares orgánicas de alta eficiencia.

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Banerjee, Utsav. "Energy-efficient protocols and hardware architectures for transport layer security." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111861.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 99-104).
The Internet of Things (IoT) has introduced a vision of an Internet where computing and sensing devices are interconnected. Digitally connected devices are encroaching on every aspect of our lives, including our homes, cars, offices, and even our bodies. Researchers estimate that there will be over 50 billion wireless connected devices by 2020 [1]. On one hand, the IoT enables fundamentally new applications, but on the other, these devices are attractive targets for cyber attackers, thus making IoT security a major concern. Datagram Transport Layer Security (DTLS) is considered to be one of the most suited protocols for securing the IoT. However, computation and communication overheads make it very expensive to implement DTLS on resource-constrained IoT sensor nodes. In this work, we profile the energy costs of DTLS version 1.3, using experimental models for cryptographic computations and radio-frequency (RF) communications. Based on this analysis, we propose protocol optimizations that can reduce the overall energy consumption of DTLS up to 45%, while still maintaining the same security strength of the standard DTLS. We discuss energy-efficient architectures for implementing the standard cryptographic primitives AES (Advanced Encryption Standard), SHA (Secure Hash Algorithm) and ECC (Elliptic Curve Cryptography) in hardware. Our hardware can provide more than 2,500 times reduction in energy consumption compared to traditional software implementations. These hardware primitives are integrated with dedicated control and memory to design a DTLS co-processor that can accelerate the complete DTLS state machine in hardware, thus minimizing the energy consumption due to DTLS computations. The proposed DTLS core is integrated with a RISC-V micro-processor to accurately profile these functions, as well as design custom protocols using standalone cryptographic instructions.
by Utsav Banerjee.
S.M.

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Pedroso, Guilherme. "Avaliação energética, econômica e socioambiental de alternativas para sistemas de transportes urbanos coletivos a partir do modelo de apoio multicritério à decisão." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/106/106131/tde-22022018-171520/.

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Essa pesquisa tem como foco a tomada de decisão para a escolha de modais de transporte urbano coletivo e analisa os desempenhos operacionais e funcionais dos sistemas Bus Rapid Transit (BRT), Veículo Leve sobre Trilhos (VLT) e Monotrilho. Um modelo de apoio multicritério à decisão (AMD) em cenários complexos é utilizado na análise e tem como dados de entrada as preferências subjetivas de agentes de decisão (stakeholders) e os desempenhos objetivos e subjetivos dos três modais com relação a um sistema de cinco critérios e 22 subcritérios. Tal sistema cobre os eixos de eficiência energética, custo, viabilidade econômica e financeira, qualidade da viagem e impactos ambientais. Stakeholders selecionados com perfis de operador, vizinho, usuário, fornecedor de equipamentos e serviços e consultor em transportes urbanos atribuem suas preferências, pontuando-as em escala numérica de 1 a 9. Visando a aplicação do modelo na região da cidade de São Paulo, foram coletadas 138 opiniões de preferências através de formulários de avaliação e entrevistas conduzidas nessa região. Cada um dos três modais, após ser configurado para atender aos requisitos operacionais e funcionais do serviço de transporte definido por uma unidade funcional comum, tem os seus desempenhos com relação ao mesmo conjunto de critérios e subcritérios pontuados em uma escala numérica. Um índice global (IG), que define a prioridade de cada alternativa, é obtido pela agregação das preferências e desempenhos com uma função aditiva. O modelo foi aplicado em um estudo de caso que simulou a operação dos três modais no trecho entre as estações Vila Prudente e São Mateus da Linha 15 do Metrô de São Paulo, cujos requisitos definiram a unidade funcional. Dentro dos limites e premissas estabelecidas para o estudo de caso, os índices globais calculados indicaram a preferência pelo modal Monotrilho, seguido, na ordem, pelo VLT e BRT.
This research focuses on decision-making support methods to choice public urban transport modes and analyzes the operational and functional performances of the Bus Rapid Transit (BRT), Light Rail Transit (LRT) and Monorail systems. A multicriteria decision aided model (MDAM) in complex scenarios is used in the analysis and has as input data the subjective preferences of stakeholders and the objective and subjective performances of the three modalities in relation to a set of five criteria and 22 subcriteria. This system covers the axes of energy efficiency, cost, economic and financial feasibility, travel quality and environmental impacts. Stakeholders selected with profiles of operator, neighbor, user, equipment and service provider and consultant in urban transport assign their preferences, scoring them on a numerical scale from 1 to 9. In order to apply the model in the region of the city of São Paulo, 138 opinions were collected through evaluation forms and interviews conducted in that region. Each of the three modes, once configured to meet the operational and functional requirements of the transport service defined by a common functional unit, has its performances against the same set of criteria and subcriteria scored on a numerical scale. A global index (GI), which defines the priority of each alternative, is obtained by aggregating the preferences and performances according to an additive function. The MDAM model was applied in a case study that has simulated the operation of the three transport modalities in the stretch between the stations Vila Prudente and São Mateus of the Line 15 of the São Paulo Metro, whose general requirements did define the functional unit of the case. Within the limits and assumptions defined for the case study, the calculated global indices indicated the first preference for the Monorail modal, followed, in sequence, by the LRT and BRT.

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Ben, Jmaa Chtourou Yomna. "Implémentation temps réel des algorithmes de tri dans les applications de transports intelligents en se basant sur l'outil de synthèse haut niveau HLS." Thesis, Valenciennes, 2019. http://www.theses.fr/2019VALE0013.

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Les systèmes de transports intelligents jouent un rôle important dans la minimisation des accidents, embouteillage, et la pollution d’air. Parmi ces systèmes, nous citons le domaine avionique qui utilise dans plusieurs cas les algorithmes de tri qui sont l’une des opérations importante pour des applications embarquées temps réels. Cependant, l’évolution technologique tend vers des architectures de plus en plus complexes pour répondre aux exigences applicatives. À cet égard, les concepteurs trouvent leur solution idéale dans l’informatique reconfigurable, basée sur des architectures hétérogènes CPU/FPGA qui abritent des processeurs multi-core (CPU) et des FPGAs qui offrent de hautes performances et une adaptabilité aux contraintes temps-réel de l’application. L’objectif principal de mes travaux est de développer une implémentions matérielle des application de transports intelligents (algorithme de planification de plan de vol A*)et les algorithmes de tri sur l’architecture hétérogène CPU/FPGA en utilisant l’outil de synthèse haut niveau pour générer le design RTL à partir de la description comportementale. Cette étape nécessite des efforts supplémentaires de la part du concepteur afin d'obtenir une implémentation matérielle efficace en utilisant plusieurs optimisations avec différents cas d’utilisation : logiciel, matérielle optimisé et non optimisé et aussi pour plusieurs permutations/vecteurs générer à l’aide d’un générateur de permutation basé sur Lehmer. Pour améliorer les performances, nous avons calculés le temps d’exécution, l’écart type et le nombre de ressource utilisé pour les algorithmes de tri en considérant plusieurs tailles de données varient entre 8 et 4096 éléments. Finalement, nous avons comparé les performances de ces algorithmes. Cet algorithme sera intégrer les applications d’aide à la décision, planification du plan de vol
Intelligent transport systems play an important role in minimizing accidents, traffic congestion, and air pollution. Among these systems, we mention the avionics domain, which uses in several cases the sorting algorithms, which are one of the important operations for real-time embedded applications. However, technological evolution is moving towards more and more complex architectures to meet the application requirements. In this respect, designers find their ideal solution in reconfigurable computing, based on heterogeneous CPU / FPGA architectures that house multi-core processors (CPUs) and FPGAs that offer high performance and adaptability to real-time constraints. Of the application. The main objective of my work is to develop hardware implementations of sorting algorithms on the heterogeneous CPU / FPGA architecture by using the high-level synthesis tool to generate the RTL design from the behavioral description. This step requires additional efforts on the part of the designer in order to obtain an efficient hardware implementation by using several optimizations with different use cases: software, optimized and nonoptimized hardware and for several permutations / vectors generated using the generator pf permutation based on Lehmer method. To improve performance, we calculated the runtime, standard deviation and resource number used for sorting algorithms by considering several data sizes ranging from 8 to 4096 items. Finally, we compared the performance of these algorithms. This algorithm will integrate the applications of decision support, planning the flight plan

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López, Vizcaíno Jorge [Verfasser], Peter [Akademischer Betreuer] Krummrich, and Andreas [Gutachter] Kirstädter. "Energy-efficient design of optical transport networks / Jorge López Vizcaíno ; Gutachter: Andreas Kirstädter ; Betreuer: Peter Krummrich." Dortmund : Universitätsbibliothek Dortmund, 2016. http://d-nb.info/1130401502/34.

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Barbosa, Maísa Ribeiro. "Mobilidade sustentável no Brasil: análise de impactos energéticos do incentivo ao transporte coletivo e da eletrificação de ônibus." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-01112018-111915/.

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A mobilidade de pessoas no mundo é não apenas um dos maiores desafios tecnológico e político do século XXI, como também uma área de alto impacto energético e ambiental. O presente trabalho busca analisar o transporte rodoviário de passageiros no Brasil pela perspectiva energética. Para a fundamentação teórica, aborda-se a dinâmica da mobilidade no mundo, alguns conceitos fundamentais e a relação entre o perfil de transportes, o perfil energético do setor e suas externalidades negativas. Em seguida, é apresentado o conceito de Mobilidade Sustentável, que busca apontar diretrizes para mitigação de externalidades e maior eficiência energética, dentre as quais estão a transição modal_ o incentivo a transportes públicos em detrimento dos individuais_ e a eletrificação de veículos. Como metodologia do trabalho, opta-se por simular os impactos energéticos de cenários brasileiros de eletrificação de ônibus (eletrificação progressiva, chegando a 71% da frota de ônibus até 2050) e de transição modal (manutenção de 35% da atividade de passageiros feita por ônibus), tanto individualmente, quanto combinados, através do modelo Global Transportation Roadmap. Os resultados mais expressivos de eficiência energética, economia de energia e demanda de eletricidade são observados na trajetória que combina ambas as estratégias, em que se chega a 105TWh de economia de energia no ano de 2050 e alcança-se uma demanda de energia elétrica de 67TWh. De 2020 a 2050, acumula-se uma economia de 7,6% da energia total demandada por transportes de ônibus e de automóvel no Brasil. Finalmente, analisam-se os resultados das simulações, suas limitações e recomendações de melhorias.
Worldwide, passenger mobility is not only one of the most significant political and technological challenges of the 21st century, but also a sector of high energetic and environmental impact. The present work aims to analyze road passenger transportation from the energy sector perspective. The theoretical basis approaches the dynamics of the mobility sector globally, some of its fundamental concepts and the nexus between transportation, energy consumption and negative externalities. Afterwards, it is conceptualized the Sustainable Mobility approach, and its guidelines for energy efficiency and externality mitigation, among which are Modal Shift (incentivizing the adoption of collective and efficient modes of transport) and vehicle electrification. The chosen work methodology is to simulate in the Global Transport Roadmap Model the energy impact of the following scenarios: 1) EB71: a progressive bus electrification scenario that achieves 71% of the national bus fleet electrified by 2050; 2) MS35: maintaining 35% of bus modal share, despite the historical records of bus-to-car shifts in the country; and 3) EB71.MS35: the combination of the previous strategies in a combined scenario. As a result, the EB71.MS35 scenario shows the highest rates of energy efficiency, energy savings and electricity demand: the projections for 2050 achieve 105TWh in energy savings and 67TWh of electricity demand. The cumulative energy saving from 2020 to 2050 reaches 7,6% of the energy demand for buses and automobiles in the same period. Finally, the simulation results are analyzed, and comments are made regarding limitations of the model, conclusions, and further steps for research.

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Dini, Alina L. "Influence of new car buyers' purchase experience on plug-in electric vehicle demand." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/116541/1/Alina_Dini_Thesis.pdf.

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Plug-in electric vehicles (PEVs) are one new technology which offers promise for transport sustainability and improving energy efficiency. Global enthusiasm for PEVs has spurred broad-reaching interest, but for jurisdictions where PEV policies are absent, as in Australia, consumer adoption continues to be low. Research into the barriers of adoption for PEVs often identifies cost and lack of infrastructure as key barriers, but consumer's purchase experience plays a pivotal role in technology adoption. This research will help the PEV industry and governments to understand how critical the consumer purchase experience is to overall market success.

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Madani, Sepideh Sadat. "Investigation of charge transport metal oxides for efficient and stable perovskite solar cells." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/235892/1/Sepideh%2BSadat%2BMadani%2BThesis%282%29.pdf.

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This research investigates various thin-film metal oxides as charge transport layer for improving the performance and stability of perovskite solar cells. Physical Vapor Deposition techniques such as magnetron sputtering, and electron beam evaporation were used to fabricate the metal oxide thin films. The structural, morphological, chemical, optical, electrical, and electronic properties of the films were studied. Solar Cell Capacitance Simulator was employed for investigating the performance of the PSC using the experimental data as input parameters. Results showed that optimized properties of the metal oxide thin films as charge (hole) transport layer have improved the performance of the PSC device.

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Galbieri, Rodrigo 1977. "O transporte rodoviário de passageiros no Brasil : estratégias de mitigação do consumo energético e da emissão de CO2." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264173.

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Orientador: Andre Felipe Simões
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: O presente Estudo possui como objetivo principal realizar uma análise quantitativa dos impactos sobre o consumo de combustíveis e das emissões de CO2 de medidas de eficiência energética e aumento no uso de biocombustíveis para o setor de transportes rodoviário brasileiro de passageiros (veículos leves, motocicletas e ônibus) - de forma isolada e conjunta - entre os anos 2010 a 2030. Concomitantemente, visa oferecer uma "cesta" de opções para os tomadores de decisões (esferas políticas) para o setor de transportes brasileiro de passageiros nas áreas de eficiência energética, combustíveis alternativos e medidas de gestão da demanda. A citada "cesta" de opções envolve aspectos qualitativos e quantitativos dessas medidas de mitigação. Para se atingir o objetivo proposto realizou-se uma análise do potencial técnico-econômico de tecnologias relacionadas à mitigação do consumo de combustíveis e das emissões de CO2, no horizonte de tempo 2010 a 2030. Já a metodologia utilizada na análise quantitativa estima a frota de veículos circulantes no Brasil, o consumo de combustíveis e as emissões de CO2 do setor de transportes rodoviário de passageiros adotando uma abordagem bottom-up. Adotou-se, como premissa, que o ano de início da implementação das medidas mitigatórios para os Cenários Alternativos seria 2015. Foi criado um Cenário Tendencial (denominado BAU - Business-as-Usual) e mais 3 grupos de cenários alternativos - modelados com diferentes padrões de aumento de eficiência energética e/ou uso de biocombustíveis (etanol anidro, etanol hidratado e biodiesel), incluindo a conversão da frota de ônibus a óleo Diesel para etanol aditivado. De acordo com os resultados apresentados pelas projeções desse Estudo, mantidas as tendências atuais até o ano de 2030, o crescimento projetado das emissões de CO2 no Cenário BAU, entre os anos de 2010 e 2030, foi de expressivos 120%. Contudo, os resultados das simulações, revelam possibilidades de mitigações das emissões de CO2 entre 5% a 48% para o caso dos cenários propostos, em relação ao Cenário BAU. Os resultados do presente Trabalho permitem intuir que as atuais políticas para promoção do uso de biocombustíveis de primeira geração no Brasil, combinadas com programas de eficiência energética veicular, incluindo hibridização, formam uma estratégia robusta de mitigação. Tais estratégias se mostram factíveis às questões envolvendo a problemática e tênue relação entre ("produção" e uso de) energia e meio ambiente, principalmente no que se refere ao uso do solo (desmatamentos e produção de alimentos). Apesar de não ter sido quantificado, em virtude das limitações do modelo escolhido, medidas de gerenciamento da demanda por transporte devem fazer parte das políticas públicas na área de transporte, pois o potencial de mitigação dessas medidas, conforme os exemplos analisados são substanciais
Abstract: The present thesis has, as the mains goal, to provide a quantitative analysis of the impacts on fuel consumption and CO2 emissions of energy efficiency measures and increased use of biofuels for the Brazilian road transport passenger sector (light vehicles, motorcycles and buses) - separately and together - between the years 2010 and 2030. Concomitantly, it aims to provide a "basket" of options to policymakers in the areas of energy efficiency, alternative fuels and demand management measures. The aforementioned "basket" of options involves qualitative and quantitative aspects of these mitigation measures. To achieve the proposed objectives, it was performed an analysis of the technical and economic potential for the mitigation technologies related to fuel consumption and CO2 emissions, considering the timeline from 2010 to 2030. It's opportune to mention that the methodology used in the quantitative analysis estimates the fleet of vehicles circulating in Brazil, fuel consumption and CO2 emissions from the transportation sector by road by adopting a bottom-up approach, as recommended by the Intergovernmental Panel on Climate Change - IPCC The results of this work indicate that current policies for promoting the use of first generation biofuels in Brazil, combined with vehicular energy efficiency programs, including hybridization, form a robust mitigation strategy. Such strategies appeared feasible to issues involving the problematic and tenuous relationship between ("production" and use of) energy and the environment, particularly with regard to land use (deforestation and food production, mainly). Despite not being quantified, due to limitations of the choose model, demand management measures should be part of public policies in the area of transportation. After all, the potential for mitigation measures, such as the analyzed examples, are substantial. In fact, the results of the simulations reveal possibilities of CO2 emission mitigation among 5% to 48% for the case of the proposed sceneries, in relation to the business as usual scenario
Mestrado
Planejamento de Sistemas Energeticos
Doutor em Planejamento de Sistemas Energéticos

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FARIAS, Fabrício de Souza. "Designing cost-efficient transport solutions for fixed and mobile broadband access network." Universidade Federal do Pará, 2016. http://repositorio.ufpa.br/jspui/handle/2011/7956.

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CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico
Esta tese se concentra na avaliação técnico econômica de soluções de transporte para acesso banda larga fixa e móvel. Para futuras redes de acesso móvel, propõem-se arquiteturas de backhaul usando fibra e microondas baseado no desenvolvimento de redes de acesso wireless verde e infraestruturas legadas de backhaul baseada em cobre para migração Brownfield, ou seja, usando infraestrutura existente até o limite de capacidade suportada, enquanto para redes de banda larga fixa são propostas implantações de proteção baseadas em esquemas híbridos, ou seja, fiber+wireless. As principais contribuições desta tese estão relacionadas ao campo de pesquisa do custo total de investimento em infraestrutura de transporte banda larga. Em termos de custo total de investimento, são propostos dois conjuntos de modelos para avaliar as despesas de capital e de operação, CAPEX e OPEX respectivamente, de operadoras de redes de acesso banda larga fixa e móvel. Primeiramente, para banda larga móvel, é apresentado um conjunto de modelos condensado em uma metodologia geral que visa fornecer: previsão de tráfego, implantação de rede sem fio, implantação de backhaul móvel e avaliação do custo total. É mostrado que o backhaul baseado em fibra considerando acesso sem fio verde é a opção mais eficiente em termos de energia. Além disso, Brownfield mostra que o backhaul baseado em cobre ainda pode desempenhar um grande papel se utilizado até a exaustão de sua capacidade e reduz drasticamente os custos de investimentos em infraestrutura. Adicionalmente, são apresentadas as principais diferenças de custos e valores de energia entre redes de acesso sem fio verde e Brownfield. Finalmente, para banda larga fixa, é proposta uma metodologia baseada em dimensionamento de rede, custos associados à falha e avaliação do custo total por assinante. Os modelos são utilizados para avaliar cinco modelos que representam diferentes esquemas de proteção para arquiteturas de banda larga fixa. Esta pesquisa revela os benefícios econômicos do uso de esquema de proteção híbrido baseado em arquitetura fiber+wireless comparado com a opção de proteção baseada totalmente em fibra e é também apresentada uma análise de sensibilidade para provar que o investimento adicional em CAPEX para proteger a infraestrutura pode ser recuperado em alguns anos através da economia em OPEX.
This thesis undertakes a techno-economic evaluation of transport solutions for fixed and mobile broadband access. In the case of future mobile access networks, it is proposed to make use of backhaul architectures using fiber and microwave applied to Greenfield deployments and a copper-legacy backhaul infrastructure based on Brownfield migration, i.e. finding a way of using a legacy infrastructure to its full capacity. At the same time, protection deployments based on fiber-wireless schemes are recommended for future fixed broadband. The main contribution made by this thesis is to carry out a research investigation into the total investment cost of the broadband transport infrastructure. This will be determined by employing two sets of models to assess the capital and operational expenditures, (CAPEX and OPEX respectively), of mobile and fixed broadband access network operators. First, this involves a set of models for mobile broadband that are summarized in a general methodology that aims at providing: traffic forecasting, wireless deployment, mobile backhaul deployment and total cost assessment. It was found that, fiber-based backhaul through a Greenfield deployment is the most energy-efficient option. Furthermore, Brownfield reveals that copper-based backhaul can still play a key role if used up to its full capacity and sharply reduces the investment costs in infrastructure. Additionally, there is an examination of the main differences in cost and energy values between Greenfield and Brownfield. Finally, a methodology is employed for fixed broadband based on network dimensioning, failure costs and an assessment of the total cost of ownership. The models are used to assess five architectures that represent different protection schemes for fixed broadband. This research shows the economic benefits of using a hybrid protection scheme based on fiber-wireless architecture rather than fiber-based protection options and a sensitivity analysis is conducted to show that the extra CAPEX invested to protect the infrastructure might be recovered through the OPEX after a number of years. The results obtained in the thesis should be useful for network operators to plan both their fixed and mobile broadband access network infrastructure in the future.

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Barhemmati, Rajab Nastaran. "Thermal Transport Properties Enhancement of Phase Change Material by Using Boron Nitride Nanomaterials for Efficient Thermal Management." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1752408/.

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In this research thermal properties enhancement of phase change material (PCM) using boron nitride nanomaterials such as nanoparticles and nanotubes is studied through experimental measurements, finite element method (FEM) through COMSOL 5.3 package and molecular dynamics simulations via equilibrium molecular dynamics simulation (EMD) with the Materials and Process Simulations (MAPS 4.3). This study includes two sections: thermal properties enhancement of inorganic salt hydrate (CaCl2∙6H2O) as the phase change material by mixing boron nitride nanoparticles (BNNPs), and thermal properties enhancement of organic phase change material (paraffin wax) as the phase change material via encapsulation into boron nitride nanotubes (BNNTs). The results of the proposed research will contribute to enhance the thermal transport properties of inorganic and organic phase change material applying nanotechnology for increasing energy efficiency of systems including electronic devices, vehicles in cold areas to overcome the cold start problem, thermal interface materials for efficient heat conduction and spacecraft in planetary missions for efficient thermal managements.

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Silva, Rui Manuel Ramos da. "Soluções sustentáveis no transporte vertical. A travagem regenerativa." Master's thesis, Instituto Superior de Economia e Gestão, 2012. http://hdl.handle.net/10400.5/10346.

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Mestrado em Gestão e Estratégia Industrial
A procura pela eficiência energética tornou-se uma responsabilidade de todos. Seja por questões ambientais, pelo escasseio de combustíveis fósseis, por cumprimento de legislações, pela procura de competitividade ou apenas pela busca de poupança é notória a insistência na utilização racional de energia, na poupança energética e na consciencialização ambiental. As empresas tentam a todo o custo encontrar soluções para fazer face a este problema e assim se manterem competitivas. Porém, a ideia de um produto inovador por si só não é suficiente para lançá-lo com sucesso no mercado existindo um trabalho importante a ser realizado antecedentemente. A presente tese tem como primeiro objetivo focar a Análise de Valor e o Teste de Conceito como duas metodologias chave para o desenvolvimento de um produto/inovação em colaboração com o cliente, de modo a satisfazer as suas necessidades pelo custo mais baixo. A inovação escolhida foi a travagem regenerativa associada ao transporte vertical permitindo a geração de energia com injeção de potência na rede contribuindo assim para a eficiência energética nos edifícios. O segundo objetivo passa por determinar a existência ou não de regeneração de energia, em que condições e quantidades tal acontece sendo para isso realizados testes práticos numa instalação real.
The energy efficiency demand has become a shared responsibility. Whether for the environmental issues, the fossil fuels extinction, the laws compliance, the competitiveness search or just for the energy saving target, it is notorious the insistence on the rational use of energy, on the energy saving and on the environmental awareness. The companies try at all costs to find solutions to tackle this problem and to remain competitive. But just an innovative product idea is not enough to throw it successfully in the market and there is a significant work to be done antecedently. The first target of this thesis is to focus the Value Analysis and Concept Testing as two key methodologies for the product/innovation development in collaboration with the client to satisfy their needs at lower cost. The chosen innovation was the regenerative braking associated to the vertical transport allowing the power generation with power injection to the electric network contributing to the energy efficiency in buildings. The second objective is to determine the energy regeneration existence or not, on what conditions and quantities it happens. For that purpose it were made practical tests in a real installation.

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Santos, Vitor Luiz Rigoti dos. "Análise experimental dos processos de transferência de calor aplicados à concentração solar." Universidade Federal do Espírito Santo, 2008. http://repositorio.ufes.br/handle/10/6243.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Having in mind the necessity to pump heavy crude oil from notoriously sunny regions of Brazil (northern Brazil regions general speaking or northern Espirito Santo state specifically), the utilization of solar radiation appears as an alternative thermal source to heat on-shore pipelines and storage tanks. The present work exhibits the basic steps to project, design, construction and test of a parabolic solar concentrator prototype, as well as shows experimental results gotten from the activities developed by the whole project and points out some possibilities to enhance the system for future operations. Here, the main objective is to increase heat transfer to a tube installed on parabolic focus (absorber tube). Using distinct configurations for the absorbers tubes, the work fluid is heated and analysis are prosecuted over collected data aiming to reach the main goal, which is to study the pressure drop reduction by viscosity decreasing of heavy oils flow using solar energy collected by a parabolic concentrator.
Tendo em vista a necessidade de transportar óleos pesados produzidos em regiões notoriamente ensolaradas do Brasil (tais como o norte do estado do Espírito Santo e estados da região Nordeste), o aproveitamento da radiação solar incidente como fonte de energia térmica alternativa para aquecimento de oleodutos e tanques de armazenamento terrestres (on-shore) surge como uma solução para a redução da perda de carga induzida no escoamento através da redução da viscosidade do fluido. O presente trabalho apresenta de modo sucinto as etapas de dimensionamento, projeto, construção e teste de um protótipo de concentrador solar parabólico, bem como os resultados experimentais obtidos durante as atividades do projeto como um todo, além de apontar também novas possibilidades de melhoria do sistema para futuras operações. A principal proposta deste trabalho é a otimização do tubo absorvedor do concentrador solar, a fim de aumentar o aproveitamento da radiação incidente. Utilizando configurações distintas de tubos absorvedores instalados sobre o foco do concentrador solar parabólico experimental, o fluido de trabalho é aquecido e, de posse dos dados coletados nos experimentos são feitas as devidas análises para alcançar o objetivo do projeto principal, que é obter uma forma de redução da perda de carga em escoamentos de óleos pesados utilizando a energia solar coletada por um concentrador parabólico.

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Le, Roux Daniël Francois. "Investigation, development and testing of a low cost Solar Heat Barrow (SHB) and purifier / D.F. le Roux." Thesis, North-West University, 2003. http://hdl.handle.net/10394/204.

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Many rural communities in South Africa do not have running water or electricity. The fetching and heating of water is therefore a time consuming and expensive daily ritual. The use of energy sources such as wood or coal are not readily available and cause environmental pollution. Although solar water heaters are commonly available in South Africa, they are very seldom used in rural areas. Whilst this can mostly be attributed to a high system cost, current designs also do not cater for specific rural problems such as the transporting or purification of water. A prototype model, designed with such an approach in mind, has already been constructed by TEMM International (Pty.) Ltd. The Solar Heat Barrow (SHB) was developed in the 1992 to 2003 period with the intention of combining a number of functions at low cost. Specific requirements were: low cost, a suitable design and materials for manufacture in large volume, sufficiently durable taking into account the harsh conditions of use. suitability for cases where no in-house piped water supply was available, the use of appropriate technology and the improvement of quality of life. The unit combines the absorption of solar radiation, the heating of a relatively small volume of water, the transport of the water from the point of supply and the storage of the hot water until it is used. Untreated water sources such as surface waters (streams, rivers, lakes, etc.) or unprotected open wells are the vehicles for waterborne bacterial diseases such as cholera and typhoid fevers. In the case where water is collected from these sources, the SHB has a build-in Purification Dispenser that purifies the water in the collector against waterborne bacterial diseases. Certain research questions need to be answered. They will be answered by demonstrating the SHB in two communities where no in-house piped water supply is available and by establishing the socio-economic response of the users. The research questions are as follow: What are the responses of the users concerning the SHB, in comparison to those of a control group, regarding its operation, durability, utility and satisfaction of needs? What is the daily use of hot water and the reduction in energy use and cost? To what extent will the target community purchase the SHB at the full or subsidised commercial price? Is there a business case that can be developed for the large scale production, marketing. financing and Small, Medium and Micro Enterprises (SMME) development of the SHB? It was decided to choose a community in the Valley of Thousand Hills in KwaZulu Natal as the demonstration site. The name of the community is Mabedlane. It is a remote rural area 20 km's north of Botha's Hill and is situated along the Umgeni River. The community is dependent on the river for domestic water. Most families are headed by women. The area has low levels of infrastructure, poor roads, a high unemployment rate and poor health facilities. The first survey, which was conducted before the test period started, showed a very positive response from potential users. From 112 questionnaires that were given to the people of Mabedlane, all indicated that they were interested in a product that can transport and heat water for domestic use. The socio-economic study has shown that the price per unit needs to be adapted as 85% of the people who participated in the survey indicated that they would only pay less than R100 for the product. 15% indicated that they would pay between RlOO and R200. From the second and third questionnaires it was clear that the users were satisfied with the heating performances of the SHB. The community was very interested in purchasing a SHB. They have realised that a SHB will improve their standard of living and regard it as a necessity in their day to day activities. It is apparent that people, who will benefit from a SHB most, are those who will not be able to pay the full retail price. Therefore, new business strategies have to be researched when implementing the SHB to the target market in South Africa. The idea of considering ways to sponsorlfund the SHB must also be investigated.
Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2004.

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Genet, Benjamin. "On monitoring methods and load modeling to improve voltage stability assessment efficiency." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210258.

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Power systems must face new challenges in the current environment. The energy market liberalization and the increase in the loading level make the occurrence of instability phenomena leading to large blackouts more likely. Existing tools must be improved and new tools must be developed to avoid them.

The aim of this thesis is the improvement of the voltage stability assessment efficiency. Two orientations are studied: the monitoring methods and the load modeling.

The purpose of the monitoring methods is to evaluate the voltage stability using only measurements and without running simulations.

The first approach considered is local. The parameters of the Thevenin equivalent seen from a load bus are assessed thanks to a stream of local voltage and current measurements. Several issues are investigated using measurements coming from complete time-domain simulations. The applicability of this approach is questioned.

The second approach is global and uses measurements acquired by a Wide-Area Measurement System (WAMS). An original approach with a certain prediction capability is proposed, along with intuitive visualizations that allow to understand the deterioration process leading to the collapse.

The load modeling quality is certainly the weak point of the voltage security assessment tools which run simulations to predict the stability of the power system depending on different evolutions. Appropriate load models with accurate parameters lead to a direct improvement of the prediction precision.

An innovative procedure starting from data of long measurement campaigns is proposed to automatically evaluate the parameters of static and dynamic load models. Real measurements taken in the Belgian power system are used to validate this approach.

Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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Nasr, Sarah. "Optimisation d’un réseau ferroviaire à l’aide de solutions smart-grids." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC026/document.

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L'amélioration de l'efficacité énergétique est devenue aujourd'hui une nécessité dans tous les domaines techniques. La réduction de la consommation, et donc du bilan carbone, est placée parmi les priorités mondiales tel que le paquet énergie-climat 2020 de l'Union Européenne.Les systèmes ferroviaires font partie des plus grands consommateurs d'énergie. Des solutions électriques sont développées pour réduire les pertes dans ces systèmes, optimiser la consommation et donc réduire la facture énergétique globale. Étant donné la diversité de ces systèmes, deux catégories principales sont considérées. La première regroupe les lignes urbaines caractérisées par une électrification en mode DC et un trafic relativement dense. Dans ce cas, l'énergie de freinage brûlée dans les rhéostats des trains constitue une perte considérable. La solution proposée consiste à récupérer cette énergie à l'aide d'un DC micro-grid installé dans une station passager. Elle permettra une interaction avec son environnement non-ferroviaire comme par exemple réutiliser cette énergie pour charger des bus électriques hybrides stationnant à proximité. Ce micro-grid contient un premier convertisseur DC/DC qui récupère l’excès d'énergie de freinage d'un train et l'injecte dans un DC busbar. Un deuxième convertisseur DC/DC va ensuite la stocker dans un système de stockage hybride pour que le bus électrique puisse se charger une fois branché au DC busbar. Le micro-grid est relié au réseau par un onduleur réversible AC/DC de faible puissance. L'ensemble est géré localement par un système gestion de puissance. Une évaluation énergétique montre que cette solution est intéressante lorsqu’un investissement, station de charge, est nécessaire pour charger les bus. En plus, dans le cas du DC micro-grid, aucun contrat avec le fournisseur d’électricité n’est nécessaire. La stabilité du système est aussi étudiée et une commande de stabilisation, le backstepping, est appliquée. Ce nouveau concept d’une future station intelligente permettra au système ferroviaire de communiquer avec son environnement qui est en pleine évolution.La deuxième catégorie est constituée par les lignes régionales et les lignes à grandes vitesses fonctionnant en mode AC. Contrairement au cas précédent, l’excès d’énergie de freinage est renvoyé à travers les sous-stations d’alimentation. Par conséquence, une deuxième solution propose la réduction de la consommation totale par l’optimisation du profile de vitesse de chaque train et la synchronisation de la grille horaire. Ceci est réalisé à l’aide d’un algorithme d’évolution différentielle. Chaque profile de vitesse est découpé en zones auxquelles sont attribuées des paramètres de conduite. L'optimisation de ces derniers permet de générer un nouveau profile de conduite optimal. Les résultats montrent la possibilité de faire des économies d’énergie tout en respectant la ponctualité des trains
Increasing energy efficiency is nowadays a requirement in all technical fields. The reduction of global consumption, thus carbon footprint, has become the world's priority, as for example, the climate and energy package of the European Union.Railways' share of energy consumption is one of the highest. Electrical solutions are developed in order to reduce these systems' losses, optimize their consumption and reduce global energy bill. Given their diversity, two main categories are considered in this study. The first one consists of urban lines that are characterized by a DC electrification and a relatively dense traffic. In this case, braking energy burned in trains' rheostats represents the main share of losses. The proposed solution is to recuperate this energy using a DC micro-grid implemented in a passengers' station. It allows an interaction with the non-railway electrical environment, for example, re-using this energy in charging electric hybrid buses parked nearby. The excess of braking energy is recuperated using a DC/DC converter and injected into a DC busbar. A second DC/DC converter will store it in a hybrid storage system. It will then serve to charge the buses connected to the DC busbar. The micro-grid is also connected to the grid using a low power AC/DC converter. A power management system ensures optimizing power flow between different components. An energy evaluation showed that this solution is a good Investment especially because no contract is needed with the energy provider. The system's stability is studied and a stabilizing command, the backstepping, is applied. This new smart station allows railways to communicate, energetically, with its evolving environment.The second category is suburban and high speed lines that are AC electrified. Contrarily to the previous case, braking energy is reinjected to the upper grid through substations. Therefore, a second solution is to reduce global energy consumption by optimizing trains' speed profiles and timetable's synchronization. It is done using a differential evolution algorithm. Each speed profile is divided into zones to which are associated driving parameters. The optimization of the latter allowed generating new optimal speed profiles and a less-consuming timetable. Simulation results showed that it is possible to make important energy savings while respecting train's punctuality

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Biaou, Ulrich. "Étude et mise en oeuvre d'une plateforme hybride basée sur du sans fil pour l'efficience énergétique et le contrôle d'accès dans le train." Thesis, Valenciennes, 2017. http://www.theses.fr/2017VALE0042/document.

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Les besoins de nouveaux services dans les rames ferroviaires ( le comptage, l’efficience énergétique, le confort et la sécurité des passagers etc.), risquent de saturer à terme les systèmes de communication filaires mis en place il y a une vingtaine d’années. Les réseaux de capteurs sans fil, par leurs avantages (déploiement facile, capacité à s’adapter à plusieurs types d’environnements, faible consommation d’énergie), ouvrent de nombreuses perspectives pour les systèmes de gestion énergétique. Le but de ce travail de thèse est d’étudier et mettre en oeuvre un réseau de capteurs sans fil à l’intérieur des trains pour l’efficience énergétique. Ainsi, quelques protocoles de communication dédiés à la gestion énergétique ont été présentés puis une étude comparative des différents réseaux de communication sans fil réalisée. Cette étude comparative a permis de faire le choix du réseau ZigBee comme étant le plus adéquat pour la plateforme. L’architecture hybride proposée permet l’utilisation du réseau IP existant comme colonne vertébrale de l’ensemble des réseaux ZigBee. Afin de tenir compte de l’effet de l’environnement ferroviaire dans la planification et le déploiement du réseau, une étude du canal de propagation, basée sur des mesures réalisées dans un métro et un wagon de RER a été menée. L’impact de la coexistence entre le ZigBee et le WiFi et de la présence humaine sur la communication du réseau sans fil a été démontré. Le prototype d’une plateforme basée sur le réseau ZigBee allant de la collecte des données à l’affichage des informations a été réalisé et testé
The need of new services in railway trains (services for metering, energy efficiency, the comfort and safety of users etc.) may eventually saturate the wired communication systems installed since twenty years ago years. The several advantages of wireless sensor networks (easy deployment, ability to adapt on different environments and low energy consumption) offer many possibilities for energy management systems. The aim of this thesis is to study and implement a wireless network sensors inside trains for energy efficiency. Thus, some communication protocols dedicated to energy management were presented and then a comparative study of the various wireless communication networks carried out. This comparative study shows that the ZigBee network is the most suitable for the platform. The proposed hybrid architecture allows the use of the existing IP network as the backbone of all ZigBee networks. In order to take into account the effect of the railway environment in the planning and deployment of the network, a study of the propagation channel was carried out, based on measurements realized in a subway and a RER car. The impact of the coexistence between ZigBee and WiFi and of the human presence on wireless communication have been demonstrated. The prototype of a platform based on the ZigBee network, allows data collection, informations traitement and monitoring, was carried out

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Melendez, Albert, and 林波波. "Measuring Energy Efficiency in Belize’s Road Passenger Transport Sector." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/41904888177658975942.

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碩士
國立中央大學
國際永續發展碩士在職專班
104
The Transport sector is one of the major energy consumers. Energy consumption in Belize is growing every year. In situations of increasing global energy demands and rising energy costs, conserving energy becomes a very important issue. Energy efficiency is one of the best and the most frequently used indicators of energy use. Energy intensity in transport is a measure of the energy efficiency in the sector. The main objective of this paper is to determine whether there was energy efficiency Belize’s Road passenger transport sector from 2000 to 2008. This paper seeks to first of all calculate and determine the level of energy efficiency within the Road passenger transport sector of Belize’s transportation sector through the use of the ASIF framework. ASIF framework measures energy intensity which is a key indicator of energy efficiency. The key parameters of energy intensity are Energy consumption, vkm and average occupancy. These parameters were determined and energy intensity was estimated. Energy intensity and energy efficiency are inversely related. A decline in energy intensity shows an improvement in energy efficiency and vice versa. Energy Intensity in Belize’s road passenger transport decreased 9.04 percent from 2000 to 2008. Consumption rate in Belize’s transportation sector decreased and vkm rate increased; this caused a decrease in energy intensity. During the period of study, there were improvements of energy efficiency in Belize’s road transport sector.

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(6689618), Tingmingke Lu. "ESSAYS ON THE ECONOMICS OF MOTOR VEHICLE ENERGY EFFICIENCY." Thesis, 2019.

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The purpose of this dissertation is to study the effectiveness of public policies in generating fuel savings and emissions reductions. I focus on applying various empirical methods to analyze consumer responses to policy changes on both extensive and intensive margins. This dissertation consists of two chapters.

In the first chapter, I compare the effectiveness of fuel taxes and product taxes on reducing gasoline consumption of new car buyers. I employ a unified data source for vehicle choice and subsequent vehicle use to estimate a random effects logit demand model that explicitly accounts for vehicle use heterogeneity. My demand estimation suggests that new car buyers fully value the fuel-saving benefits from improved vehicle fuel efficiency when they initially purchase their cars. My policy simulations indicate that high-mileage drivers are more responsive to a change in fuel taxes than to a change in product taxes, even as low-mileage drivers are more responsive to product taxes. By capturing such heterogeneous consumer response to policies, I show that a counterfactual increase of the fuel tax is more effective than a revenue-equivalent product tax in reducing the total gasoline consumption of new car buyers. Further, when accounting for its effects on consumer response on both extensive and intensive margins, a change in fuel taxes has a clear advantage over a change in product taxes in reducing the consumption of gasoline even when the magnitude of tax increase is small. More importantly, a model not accounting for vehicle use heterogeneity understates the fuel saving effects of both policies and misleads us about the relative effectiveness when comparing different policies.

The second chapter explores how changes in the marginal cost of driving affect consumers decisions about passenger vehicle utilization, as measured by average daily miles traveled per vehicle. This intensive margin of consumer response has important implications for the effectiveness of usage-based policies, such as the fuel tax and the mileage tax, that designed to address externalities of driving. I estimate the elasticity of driving with respect to fuel cost per mile using a large panel data that covers 351 towns and cities in Massachusetts over 24 quarters. While most researchers in this literature apply fixed effects estimators to examine the elasticity of driving, I use a factor model econometric setup to account for unobserved common factors and regional heterogeneity. Residual diagnostics confirm that the factor model setup does a better job of removing the cross-section dependence than fixed effects estimators do. Given low consumer responsiveness to changes in the marginal cost of driving engendered by current usage-based policies, rights-based approaches like congestion charges might be better alternatives to influence vehicle utilization and vehicle ownership.

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Simões, Catarina Cerqueira da Silva. "Bipolar Membrane Based Energy Storage System: The Acid Base Flow Battery." Master's thesis, 2018. http://hdl.handle.net/10362/47947.

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AYADI, Ahmed. "L'efficacité énergétique des protocoles de transport fiables pour les réseaux sans fil à faible consommation d'énergie." Phd thesis, 2012. http://tel.archives-ouvertes.fr/tel-00741994.

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Low power and Lossy Networks (LLNs) such as wireless sensor networks are currently used in many important applications fields such as remote environment monitoring and target tracking. This deployment has been enabled by the availability, especially in recent years, of embedded micro-controller devices that are smaller and cheaper. These devices are equipped with wireless interfaces, with which they can communicate with each other to form a network. In this thesis we focus on studying the energy consumption of reliable transport protocols over LLNs. Recently, much research has been carried out to improve the reliability and the congestion control on low power networks. Some of these works have considered TCP inappropriate for this kind of networks. Indeed, the idea of deploying TCP was rejected due to its header overhead, its end-to-end retransmission mechanism, its large rate of acknowledgment, and the impact of the lower layers fragmentation on the energy consumption. Nonetheless, the use of standard TCP/IP protocols offers the advantage of a seamless connectivity between the wireless network and the Internet. TCP allows easily the use of standard applications (HTTP, SSH) for some tasks like reprogramming of nodes or firmware updates, without the need of deploying complex proxies in border routers. In the first part of this work, we study the energy consumption of TCP and the ways that reduce its energy consumption. We study one of the proposed TCP algorithms to reduce the end-to-end retransmissions cost and we propose some improvements that allow it to reduce the energy consumption. Then, we study the compression of the TCP header over low-power and lossy networks and we consider IPv6 over Low power Wireless Personnel Area Networks (6LoWPAN) as an example. We propose a new TCP header compression algorithm that reduces the TCP header size to about six bytes. In the second part, we propose a mathematical model that allows to estimate the energy consumption of wireless nodes. Using the model, we study the tradeoff between sending long and short TCP segments and their impact on the energy consumption. Finally, we study the impact of a new fragment recovery mechanism on the energy performance of TCP.

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Xie, Zongli. "Hybrid organic-inorganic pervaporation membranes for desalination." Thesis, 2012. https://vuir.vu.edu.au/21443/.

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Membrane desalination using reverse osmosis (RO) has been the leading candidate technology for supplying fresh water in recent years. However, there is a strong motivation for improving the established membrane process and/or developing alternative membrane technologies to overcome the limitations of high energy cost and brine discharge problems of RO technology. In the later context, pervaporation is a potential membrane technology as it has the advantage that the energy need is essentially independent of the concentration of the salt feed water. The pervaporation process combines the evaporation of volatile components of a mixture with their permeation through a nonporous polymeric membrane under reduced pressure conditions. In desalination applications, pervaporation has the advantage of near 100% of salt rejection. The pervaporation of an aqueous salt solution can be regarded as separation of a pseudo-liquid mixture containing free water molecules and bulkier hydrated ions formed in solution upon dissociation of the salt in water. Previous studies have demonstrated the possibility of applying pervaporation to produce distilled water from aqueous salt solutions. However, the water flux reported in the literature so far is generally quite low (<6 kg/m2·hr). It is believed that one of the main limitations for desalination using pervaporation is the lack of the high performance membranes with both high permeate flux and good salt rejection.

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Χριστουλάκη, Αναστασία. "Μελέτη των συνθηκών ανοδίωσης για την παραγωγή μεμβρανών πορώδους αλουμίνας με ελεγχόμενα χαρακτηριστικά." Thesis, 2014. http://hdl.handle.net/10889/8114.

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Στην παρούσα εργασία μελετάται πειραματικά η ανάπτυξη μεμβρανών πορώδους αλουμίνας με ελεγχόμενο πάχος, διάμετρο πόρου, σε ηλεκτρολύτη οξαλικού οξέος συγκεντρώσεως 0.3Μ με εφαρμοζόμενη τάση 40V και 50V. Για την κατανόηση του μηχανισμού της δημιουργίας των μεμβρανών πορώδους αλουμίνας γίνεται μια βιβλιογραφική παρουσίαση των μοντέλων ανάπτυξης της. Από τα πειράματα προκύπτει ότι ο ρυθμός ανάπτυξης του πάχους της μεμβράνης ακολουθεί τον νόμο του Faraday με απόδοση που εξαρτάται από την τάση ανοδίωσης. Τέλος υπολογίζεται η ενέργεια ενεργοποίησης για την αντίδραση του σχηματισμού της πορώδους αλουμίνας. Η ενέργεια ενεργοποίησης που αφορά την αντίδραση του αλουμινίου με τον ηλεκτρολύτη.
Ιn the present study, the synthesis of porous alumina membranes with controlled thickness and pore diameter is investigated. More specifically, the experimental condition under study was oxalic acid 0.3M under an applied voltage of 40V and 50V. In order to understand the growth mechanism of the porous alumina membrane formation, a bibliographic view of the growth models is presented. The experiments result in the conclusion that the thickness growth rate of the porous alumina membrane obeys the Faraday law for electrolysis with an efficiency being dependent on the anodization applied voltage. Finally, the activation energy for the porous alumina formation concerning the reaction of aluminum with the electrolyte, is calculated.

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Zhang, Haibo. "Efficient data transport in wireless sensor networks." 2009. http://hdl.handle.net/2440/56028.

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Providing efficient data transport is one of the uppermost objectives in the design of wireless sensor networks (WSNs) since the primary role for each sensor is to report the sensed data to the data sink(s). This thesis focuses on designing efficient data transport schemes for WSNs in the dimensions of energy consumption and time respectively. The developed schemes can be directly applied in a number of applications such as intrusion detection, target tracking, environment monitoring, etc., and can be further extended to underwater acoustic sensor networks and unmanned aerial vehicles (UAVs) networks. With the development of WSN technologies, new challenging research problems such as real-time streaming data gathering and intelligent data communication are emerging. This thesis provides useful foundation for designing next-generation data transport schemes for WSNs. Energy is the most important resource in WSNs because sensor nodes are commonly powered by small batteries, and energy is directly related to the lifetime of nodes and the network. In this thesis, energy-efficient data transport schemes are designed for two major types of WSNs: event-driven sensor networks and time-driven sensor networks. A novel on-line routing scheme called EBGR (Energy-efficient Beaconless Geographic Routing) is designed for event-driven sensor networks characterized by dynamic network topology. The main advantage of EBGR is that it can provide energy-efficient sensor-to-sink routing without any prior neighborhood knowledge. Moreover, the total energy consumption for sensor-to-sink data delivery under EBGR has an upper bound. Time-driven sensor networks, in which all sensors periodically report the sensed data to the sink(s), have been widely used for environment monitoring applications. Unbalanced energy consumption is an inherent problem in time-driven sensor networks. An efficient data gathering scheme, called EBDG (Energy-Balanced Data Gathering), is designed to balance energy consumption for the goal of maximizing network lifetime. Combing all advantages of corona-based network division,mixed-routing and data aggregation, EBDG can prolong network lifetime by an order of magnitude compared with conventional schemes. Time-efficient data transport is another critical issue in WSNs since the data generated by the sensor nodes may become outdated after a certain time interval. This thesis focuses on the problem of providing real-time data gathering in time-driven sensor networks. A novel data gathering scheme based on random access is proposed with the objective to minimize the average duration for completing one round of data gathering. Fully localized solutions have been designed for both linear networks and tree networks. A simple data gathering protocol called RADG (Random Access Data Gathering) is designed. Simulation results show that RADG outperforms CSMA based schemes when the size of the data packets is small.
Thesis (Ph.D.) -- University of Adelaide, School of Computer Science, 2009

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50

Zhang, Haibo. "Efficient data transport in wireless sensor networks." Thesis, 2009. http://hdl.handle.net/2440/56028.

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Abstract:

Providing efficient data transport is one of the uppermost objectives in the design of wireless sensor networks (WSNs) since the primary role for each sensor is to report the sensed data to the data sink(s). This thesis focuses on designing efficient data transport schemes for WSNs in the dimensions of energy consumption and time respectively. The developed schemes can be directly applied in a number of applications such as intrusion detection, target tracking, environment monitoring, etc., and can be further extended to underwater acoustic sensor networks and unmanned aerial vehicles (UAVs) networks. With the development of WSN technologies, new challenging research problems such as real-time streaming data gathering and intelligent data communication are emerging. This thesis provides useful foundation for designing next-generation data transport schemes for WSNs. Energy is the most important resource in WSNs because sensor nodes are commonly powered by small batteries, and energy is directly related to the lifetime of nodes and the network. In this thesis, energy-efficient data transport schemes are designed for two major types of WSNs: event-driven sensor networks and time-driven sensor networks. A novel on-line routing scheme called EBGR (Energy-efficient Beaconless Geographic Routing) is designed for event-driven sensor networks characterized by dynamic network topology. The main advantage of EBGR is that it can provide energy-efficient sensor-to-sink routing without any prior neighborhood knowledge. Moreover, the total energy consumption for sensor-to-sink data delivery under EBGR has an upper bound. Time-driven sensor networks, in which all sensors periodically report the sensed data to the sink(s), have been widely used for environment monitoring applications. Unbalanced energy consumption is an inherent problem in time-driven sensor networks. An efficient data gathering scheme, called EBDG (Energy-Balanced Data Gathering), is designed to balance energy consumption for the goal of maximizing network lifetime. Combing all advantages of corona-based network division,mixed-routing and data aggregation, EBDG can prolong network lifetime by an order of magnitude compared with conventional schemes. Time-efficient data transport is another critical issue in WSNs since the data generated by the sensor nodes may become outdated after a certain time interval. This thesis focuses on the problem of providing real-time data gathering in time-driven sensor networks. A novel data gathering scheme based on random access is proposed with the objective to minimize the average duration for completing one round of data gathering. Fully localized solutions have been designed for both linear networks and tree networks. A simple data gathering protocol called RADG (Random Access Data Gathering) is designed. Simulation results show that RADG outperforms CSMA based schemes when the size of the data packets is small.
Thesis (Ph.D.) -- University of Adelaide, School of Computer Science, 2009

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